970d35941313771ebaf2f6d7f6c9bd1d96d8cdcbc0fdaef7295715b4a06cc1bc

third-party/DPVO/DPViewer/pybind11/LICENSE

@@ -0,0 +1,29 @@
+Copyright (c) 2016 Wenzel Jakob <[email protected]>, All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its contributors
+   may be used to endorse or promote products derived from this software
+   without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+Please also refer to the file .github/CONTRIBUTING.md, which clarifies licensing of
+external contributions to this project including patches, pull requests, etc.

third-party/DPVO/DPViewer/pybind11/MANIFEST.in

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+recursive-include pybind11/include/pybind11 *.h
+recursive-include pybind11 *.py
+recursive-include pybind11 py.typed
+include pybind11/share/cmake/pybind11/*.cmake
+include LICENSE README.rst pyproject.toml setup.py setup.cfg

third-party/DPVO/DPViewer/pybind11/README.rst

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+.. figure:: https://github.com/pybind/pybind11/raw/master/docs/pybind11-logo.png
+   :alt: pybind11 logo
+
+**pybind11 — Seamless operability between C++11 and Python**
+
+|Latest Documentation Status| |Stable Documentation Status| |Gitter chat| |GitHub Discussions| |CI| |Build status|
+
+|Repology| |PyPI package| |Conda-forge| |Python Versions|
+
+`Setuptools example <https://github.com/pybind/python_example>`_
+• `Scikit-build example <https://github.com/pybind/scikit_build_example>`_
+• `CMake example <https://github.com/pybind/cmake_example>`_
+
+.. start
+
+
+**pybind11** is a lightweight header-only library that exposes C++ types
+in Python and vice versa, mainly to create Python bindings of existing
+C++ code. Its goals and syntax are similar to the excellent
+`Boost.Python <http://www.boost.org/doc/libs/1_58_0/libs/python/doc/>`_
+library by David Abrahams: to minimize boilerplate code in traditional
+extension modules by inferring type information using compile-time
+introspection.
+
+The main issue with Boost.Python—and the reason for creating such a
+similar project—is Boost. Boost is an enormously large and complex suite
+of utility libraries that works with almost every C++ compiler in
+existence. This compatibility has its cost: arcane template tricks and
+workarounds are necessary to support the oldest and buggiest of compiler
+specimens. Now that C++11-compatible compilers are widely available,
+this heavy machinery has become an excessively large and unnecessary
+dependency.
+
+Think of this library as a tiny self-contained version of Boost.Python
+with everything stripped away that isn't relevant for binding
+generation. Without comments, the core header files only require ~4K
+lines of code and depend on Python (3.6+, or PyPy) and the C++
+standard library. This compact implementation was possible thanks to
+some of the new C++11 language features (specifically: tuples, lambda
+functions and variadic templates). Since its creation, this library has
+grown beyond Boost.Python in many ways, leading to dramatically simpler
+binding code in many common situations.
+
+Tutorial and reference documentation is provided at
+`pybind11.readthedocs.io <https://pybind11.readthedocs.io/en/latest>`_.
+A PDF version of the manual is available
+`here <https://pybind11.readthedocs.io/_/downloads/en/latest/pdf/>`_.
+And the source code is always available at
+`github.com/pybind/pybind11 <https://github.com/pybind/pybind11>`_.
+
+
+Core features
+-------------
+
+
+pybind11 can map the following core C++ features to Python:
+
+- Functions accepting and returning custom data structures per value,
+  reference, or pointer
+- Instance methods and static methods
+- Overloaded functions
+- Instance attributes and static attributes
+- Arbitrary exception types
+- Enumerations
+- Callbacks
+- Iterators and ranges
+- Custom operators
+- Single and multiple inheritance
+- STL data structures
+- Smart pointers with reference counting like ``std::shared_ptr``
+- Internal references with correct reference counting
+- C++ classes with virtual (and pure virtual) methods can be extended
+  in Python
+
+Goodies
+-------
+
+In addition to the core functionality, pybind11 provides some extra
+goodies:
+
+- Python 3.6+, and PyPy3 7.3 are supported with an implementation-agnostic
+  interface (pybind11 2.9 was the last version to support Python 2 and 3.5).
+
+- It is possible to bind C++11 lambda functions with captured
+  variables. The lambda capture data is stored inside the resulting
+  Python function object.
+
+- pybind11 uses C++11 move constructors and move assignment operators
+  whenever possible to efficiently transfer custom data types.
+
+- It's easy to expose the internal storage of custom data types through
+  Pythons' buffer protocols. This is handy e.g. for fast conversion
+  between C++ matrix classes like Eigen and NumPy without expensive
+  copy operations.
+
+- pybind11 can automatically vectorize functions so that they are
+  transparently applied to all entries of one or more NumPy array
+  arguments.
+
+- Python's slice-based access and assignment operations can be
+  supported with just a few lines of code.
+
+- Everything is contained in just a few header files; there is no need
+  to link against any additional libraries.
+
+- Binaries are generally smaller by a factor of at least 2 compared to
+  equivalent bindings generated by Boost.Python. A recent pybind11
+  conversion of PyRosetta, an enormous Boost.Python binding project,
+  `reported <https://graylab.jhu.edu/Sergey/2016.RosettaCon/PyRosetta-4.pdf>`_
+  a binary size reduction of **5.4x** and compile time reduction by
+  **5.8x**.
+
+- Function signatures are precomputed at compile time (using
+  ``constexpr``), leading to smaller binaries.
+
+- With little extra effort, C++ types can be pickled and unpickled
+  similar to regular Python objects.
+
+Supported compilers
+-------------------
+
+1. Clang/LLVM 3.3 or newer (for Apple Xcode's clang, this is 5.0.0 or
+   newer)
+2. GCC 4.8 or newer
+3. Microsoft Visual Studio 2017 or newer
+4. Intel classic C++ compiler 18 or newer (ICC 20.2 tested in CI)
+5. Cygwin/GCC (previously tested on 2.5.1)
+6. NVCC (CUDA 11.0 tested in CI)
+7. NVIDIA PGI (20.9 tested in CI)
+
+About
+-----
+
+This project was created by `Wenzel
+Jakob <http://rgl.epfl.ch/people/wjakob>`_. Significant features and/or
+improvements to the code were contributed by Jonas Adler, Lori A. Burns,
+Sylvain Corlay, Eric Cousineau, Aaron Gokaslan, Ralf Grosse-Kunstleve, Trent Houliston, Axel
+Huebl, @hulucc, Yannick Jadoul, Sergey Lyskov Johan Mabille, Tomasz Miąsko,
+Dean Moldovan, Ben Pritchard, Jason Rhinelander, Boris Schäling, Pim
+Schellart, Henry Schreiner, Ivan Smirnov, Boris Staletic, and Patrick Stewart.
+
+We thank Google for a generous financial contribution to the continuous
+integration infrastructure used by this project.
+
+
+Contributing
+~~~~~~~~~~~~
+
+See the `contributing
+guide <https://github.com/pybind/pybind11/blob/master/.github/CONTRIBUTING.md>`_
+for information on building and contributing to pybind11.
+
+License
+~~~~~~~
+
+pybind11 is provided under a BSD-style license that can be found in the
+`LICENSE <https://github.com/pybind/pybind11/blob/master/LICENSE>`_
+file. By using, distributing, or contributing to this project, you agree
+to the terms and conditions of this license.
+
+.. |Latest Documentation Status| image:: https://readthedocs.org/projects/pybind11/badge?version=latest
+   :target: http://pybind11.readthedocs.org/en/latest
+.. |Stable Documentation Status| image:: https://img.shields.io/badge/docs-stable-blue.svg
+   :target: http://pybind11.readthedocs.org/en/stable
+.. |Gitter chat| image:: https://img.shields.io/gitter/room/gitterHQ/gitter.svg
+   :target: https://gitter.im/pybind/Lobby
+.. |CI| image:: https://github.com/pybind/pybind11/workflows/CI/badge.svg
+   :target: https://github.com/pybind/pybind11/actions
+.. |Build status| image:: https://ci.appveyor.com/api/projects/status/riaj54pn4h08xy40?svg=true
+   :target: https://ci.appveyor.com/project/wjakob/pybind11
+.. |PyPI package| image:: https://img.shields.io/pypi/v/pybind11.svg
+   :target: https://pypi.org/project/pybind11/
+.. |Conda-forge| image:: https://img.shields.io/conda/vn/conda-forge/pybind11.svg
+   :target: https://github.com/conda-forge/pybind11-feedstock
+.. |Repology| image:: https://repology.org/badge/latest-versions/python:pybind11.svg
+   :target: https://repology.org/project/python:pybind11/versions
+.. |Python Versions| image:: https://img.shields.io/pypi/pyversions/pybind11.svg
+   :target: https://pypi.org/project/pybind11/
+.. |GitHub Discussions| image:: https://img.shields.io/static/v1?label=Discussions&message=Ask&color=blue&logo=github
+   :target: https://github.com/pybind/pybind11/discussions

third-party/DPVO/DPViewer/pybind11/include/pybind11/embed.h

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+/*
+    pybind11/embed.h: Support for embedding the interpreter
+
+    Copyright (c) 2017 Wenzel Jakob <[email protected]>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "pybind11.h"
+#include "eval.h"
+
+#include <memory>
+#include <vector>
+
+#if defined(PYPY_VERSION)
+#    error Embedding the interpreter is not supported with PyPy
+#endif
+
+#define PYBIND11_EMBEDDED_MODULE_IMPL(name)                                                       \
+    extern "C" PyObject *pybind11_init_impl_##name();                                             \
+    extern "C" PyObject *pybind11_init_impl_##name() { return pybind11_init_wrapper_##name(); }
+
+/** \rst
+    Add a new module to the table of builtins for the interpreter. Must be
+    defined in global scope. The first macro parameter is the name of the
+    module (without quotes). The second parameter is the variable which will
+    be used as the interface to add functions and classes to the module.
+
+    .. code-block:: cpp
+
+        PYBIND11_EMBEDDED_MODULE(example, m) {
+            // ... initialize functions and classes here
+            m.def("foo", []() {
+                return "Hello, World!";
+            });
+        }
+ \endrst */
+#define PYBIND11_EMBEDDED_MODULE(name, variable)                                                  \
+    static ::pybind11::module_::module_def PYBIND11_CONCAT(pybind11_module_def_, name);           \
+    static void PYBIND11_CONCAT(pybind11_init_, name)(::pybind11::module_ &);                     \
+    static PyObject PYBIND11_CONCAT(*pybind11_init_wrapper_, name)() {                            \
+        auto m = ::pybind11::module_::create_extension_module(                                    \
+            PYBIND11_TOSTRING(name), nullptr, &PYBIND11_CONCAT(pybind11_module_def_, name));      \
+        try {                                                                                     \
+            PYBIND11_CONCAT(pybind11_init_, name)(m);                                             \
+            return m.ptr();                                                                       \
+        }                                                                                         \
+        PYBIND11_CATCH_INIT_EXCEPTIONS                                                            \
+    }                                                                                             \
+    PYBIND11_EMBEDDED_MODULE_IMPL(name)                                                           \
+    ::pybind11::detail::embedded_module PYBIND11_CONCAT(pybind11_module_, name)(                  \
+        PYBIND11_TOSTRING(name), PYBIND11_CONCAT(pybind11_init_impl_, name));                     \
+    void PYBIND11_CONCAT(pybind11_init_, name)(::pybind11::module_                                \
+                                               & variable) // NOLINT(bugprone-macro-parentheses)
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+/// Python 2.7/3.x compatible version of `PyImport_AppendInittab` and error checks.
+struct embedded_module {
+    using init_t = PyObject *(*) ();
+    embedded_module(const char *name, init_t init) {
+        if (Py_IsInitialized() != 0) {
+            pybind11_fail("Can't add new modules after the interpreter has been initialized");
+        }
+
+        auto result = PyImport_AppendInittab(name, init);
+        if (result == -1) {
+            pybind11_fail("Insufficient memory to add a new module");
+        }
+    }
+};
+
+struct wide_char_arg_deleter {
+    void operator()(wchar_t *ptr) const {
+        // API docs: https://docs.python.org/3/c-api/sys.html#c.Py_DecodeLocale
+        PyMem_RawFree(ptr);
+    }
+};
+
+inline wchar_t *widen_chars(const char *safe_arg) {
+    wchar_t *widened_arg = Py_DecodeLocale(safe_arg, nullptr);
+    return widened_arg;
+}
+
+/// Python 2.x/3.x-compatible version of `PySys_SetArgv`
+inline void set_interpreter_argv(int argc, const char *const *argv, bool add_program_dir_to_path) {
+    // Before it was special-cased in python 3.8, passing an empty or null argv
+    // caused a segfault, so we have to reimplement the special case ourselves.
+    bool special_case = (argv == nullptr || argc <= 0);
+
+    const char *const empty_argv[]{"\0"};
+    const char *const *safe_argv = special_case ? empty_argv : argv;
+    if (special_case) {
+        argc = 1;
+    }
+
+    auto argv_size = static_cast<size_t>(argc);
+    // SetArgv* on python 3 takes wchar_t, so we have to convert.
+    std::unique_ptr<wchar_t *[]> widened_argv(new wchar_t *[argv_size]);
+    std::vector<std::unique_ptr<wchar_t[], wide_char_arg_deleter>> widened_argv_entries;
+    widened_argv_entries.reserve(argv_size);
+    for (size_t ii = 0; ii < argv_size; ++ii) {
+        widened_argv_entries.emplace_back(widen_chars(safe_argv[ii]));
+        if (!widened_argv_entries.back()) {
+            // A null here indicates a character-encoding failure or the python
+            // interpreter out of memory. Give up.
+            return;
+        }
+        widened_argv[ii] = widened_argv_entries.back().get();
+    }
+
+    auto *pysys_argv = widened_argv.get();
+    PySys_SetArgvEx(argc, pysys_argv, static_cast<int>(add_program_dir_to_path));
+}
+
+PYBIND11_NAMESPACE_END(detail)
+
+/** \rst
+    Initialize the Python interpreter. No other pybind11 or CPython API functions can be
+    called before this is done; with the exception of `PYBIND11_EMBEDDED_MODULE`. The
+    optional `init_signal_handlers` parameter can be used to skip the registration of
+    signal handlers (see the `Python documentation`_ for details). Calling this function
+    again after the interpreter has already been initialized is a fatal error.
+
+    If initializing the Python interpreter fails, then the program is terminated.  (This
+    is controlled by the CPython runtime and is an exception to pybind11's normal behavior
+    of throwing exceptions on errors.)
+
+    The remaining optional parameters, `argc`, `argv`, and `add_program_dir_to_path` are
+    used to populate ``sys.argv`` and ``sys.path``.
+    See the |PySys_SetArgvEx documentation|_ for details.
+
+    .. _Python documentation: https://docs.python.org/3/c-api/init.html#c.Py_InitializeEx
+    .. |PySys_SetArgvEx documentation| replace:: ``PySys_SetArgvEx`` documentation
+    .. _PySys_SetArgvEx documentation: https://docs.python.org/3/c-api/init.html#c.PySys_SetArgvEx
+ \endrst */
+inline void initialize_interpreter(bool init_signal_handlers = true,
+                                   int argc = 0,
+                                   const char *const *argv = nullptr,
+                                   bool add_program_dir_to_path = true) {
+    if (Py_IsInitialized() != 0) {
+        pybind11_fail("The interpreter is already running");
+    }
+
+    Py_InitializeEx(init_signal_handlers ? 1 : 0);
+
+    detail::set_interpreter_argv(argc, argv, add_program_dir_to_path);
+}
+
+/** \rst
+    Shut down the Python interpreter. No pybind11 or CPython API functions can be called
+    after this. In addition, pybind11 objects must not outlive the interpreter:
+
+    .. code-block:: cpp
+
+        { // BAD
+            py::initialize_interpreter();
+            auto hello = py::str("Hello, World!");
+            py::finalize_interpreter();
+        } // <-- BOOM, hello's destructor is called after interpreter shutdown
+
+        { // GOOD
+            py::initialize_interpreter();
+            { // scoped
+                auto hello = py::str("Hello, World!");
+            } // <-- OK, hello is cleaned up properly
+            py::finalize_interpreter();
+        }
+
+        { // BETTER
+            py::scoped_interpreter guard{};
+            auto hello = py::str("Hello, World!");
+        }
+
+    .. warning::
+
+        The interpreter can be restarted by calling `initialize_interpreter` again.
+        Modules created using pybind11 can be safely re-initialized. However, Python
+        itself cannot completely unload binary extension modules and there are several
+        caveats with regard to interpreter restarting. All the details can be found
+        in the CPython documentation. In short, not all interpreter memory may be
+        freed, either due to reference cycles or user-created global data.
+
+ \endrst */
+inline void finalize_interpreter() {
+    handle builtins(PyEval_GetBuiltins());
+    const char *id = PYBIND11_INTERNALS_ID;
+
+    // Get the internals pointer (without creating it if it doesn't exist).  It's possible for the
+    // internals to be created during Py_Finalize() (e.g. if a py::capsule calls `get_internals()`
+    // during destruction), so we get the pointer-pointer here and check it after Py_Finalize().
+    detail::internals **internals_ptr_ptr = detail::get_internals_pp();
+    // It could also be stashed in builtins, so look there too:
+    if (builtins.contains(id) && isinstance<capsule>(builtins[id])) {
+        internals_ptr_ptr = capsule(builtins[id]);
+    }
+    // Local internals contains data managed by the current interpreter, so we must clear them to
+    // avoid undefined behaviors when initializing another interpreter
+    detail::get_local_internals().registered_types_cpp.clear();
+    detail::get_local_internals().registered_exception_translators.clear();
+
+    Py_Finalize();
+
+    if (internals_ptr_ptr) {
+        delete *internals_ptr_ptr;
+        *internals_ptr_ptr = nullptr;
+    }
+}
+
+/** \rst
+    Scope guard version of `initialize_interpreter` and `finalize_interpreter`.
+    This a move-only guard and only a single instance can exist.
+
+    See `initialize_interpreter` for a discussion of its constructor arguments.
+
+    .. code-block:: cpp
+
+        #include <pybind11/embed.h>
+
+        int main() {
+            py::scoped_interpreter guard{};
+            py::print(Hello, World!);
+        } // <-- interpreter shutdown
+ \endrst */
+class scoped_interpreter {
+public:
+    explicit scoped_interpreter(bool init_signal_handlers = true,
+                                int argc = 0,
+                                const char *const *argv = nullptr,
+                                bool add_program_dir_to_path = true) {
+        initialize_interpreter(init_signal_handlers, argc, argv, add_program_dir_to_path);
+    }
+
+    scoped_interpreter(const scoped_interpreter &) = delete;
+    scoped_interpreter(scoped_interpreter &&other) noexcept { other.is_valid = false; }
+    scoped_interpreter &operator=(const scoped_interpreter &) = delete;
+    scoped_interpreter &operator=(scoped_interpreter &&) = delete;
+
+    ~scoped_interpreter() {
+        if (is_valid) {
+            finalize_interpreter();
+        }
+    }
+
+private:
+    bool is_valid = true;
+};
+
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

third-party/DPVO/DPViewer/pybind11/include/pybind11/eval.h

@@ -0,0 +1,156 @@
+/*
+    pybind11/eval.h: Support for evaluating Python expressions and statements
+    from strings and files
+
+    Copyright (c) 2016 Klemens Morgenstern <[email protected]> and
+                       Wenzel Jakob <[email protected]>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "pybind11.h"
+
+#include <utility>
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+inline void ensure_builtins_in_globals(object &global) {
+#if defined(PYPY_VERSION) || PY_VERSION_HEX < 0x03080000
+    // Running exec and eval adds `builtins` module under `__builtins__` key to
+    // globals if not yet present.  Python 3.8 made PyRun_String behave
+    // similarly. Let's also do that for older versions, for consistency. This
+    // was missing from PyPy3.8 7.3.7.
+    if (!global.contains("__builtins__"))
+        global["__builtins__"] = module_::import(PYBIND11_BUILTINS_MODULE);
+#else
+    (void) global;
+#endif
+}
+
+PYBIND11_NAMESPACE_END(detail)
+
+enum eval_mode {
+    /// Evaluate a string containing an isolated expression
+    eval_expr,
+
+    /// Evaluate a string containing a single statement. Returns \c none
+    eval_single_statement,
+
+    /// Evaluate a string containing a sequence of statement. Returns \c none
+    eval_statements
+};
+
+template <eval_mode mode = eval_expr>
+object eval(const str &expr, object global = globals(), object local = object()) {
+    if (!local) {
+        local = global;
+    }
+
+    detail::ensure_builtins_in_globals(global);
+
+    /* PyRun_String does not accept a PyObject / encoding specifier,
+       this seems to be the only alternative */
+    std::string buffer = "# -*- coding: utf-8 -*-\n" + (std::string) expr;
+
+    int start = 0;
+    switch (mode) {
+        case eval_expr:
+            start = Py_eval_input;
+            break;
+        case eval_single_statement:
+            start = Py_single_input;
+            break;
+        case eval_statements:
+            start = Py_file_input;
+            break;
+        default:
+            pybind11_fail("invalid evaluation mode");
+    }
+
+    PyObject *result = PyRun_String(buffer.c_str(), start, global.ptr(), local.ptr());
+    if (!result) {
+        throw error_already_set();
+    }
+    return reinterpret_steal<object>(result);
+}
+
+template <eval_mode mode = eval_expr, size_t N>
+object eval(const char (&s)[N], object global = globals(), object local = object()) {
+    /* Support raw string literals by removing common leading whitespace */
+    auto expr = (s[0] == '\n') ? str(module_::import("textwrap").attr("dedent")(s)) : str(s);
+    return eval<mode>(expr, std::move(global), std::move(local));
+}
+
+inline void exec(const str &expr, object global = globals(), object local = object()) {
+    eval<eval_statements>(expr, std::move(global), std::move(local));
+}
+
+template <size_t N>
+void exec(const char (&s)[N], object global = globals(), object local = object()) {
+    eval<eval_statements>(s, std::move(global), std::move(local));
+}
+
+#if defined(PYPY_VERSION)
+template <eval_mode mode = eval_statements>
+object eval_file(str, object, object) {
+    pybind11_fail("eval_file not supported in PyPy3. Use eval");
+}
+template <eval_mode mode = eval_statements>
+object eval_file(str, object) {
+    pybind11_fail("eval_file not supported in PyPy3. Use eval");
+}
+template <eval_mode mode = eval_statements>
+object eval_file(str) {
+    pybind11_fail("eval_file not supported in PyPy3. Use eval");
+}
+#else
+template <eval_mode mode = eval_statements>
+object eval_file(str fname, object global = globals(), object local = object()) {
+    if (!local) {
+        local = global;
+    }
+
+    detail::ensure_builtins_in_globals(global);
+
+    int start = 0;
+    switch (mode) {
+        case eval_expr:
+            start = Py_eval_input;
+            break;
+        case eval_single_statement:
+            start = Py_single_input;
+            break;
+        case eval_statements:
+            start = Py_file_input;
+            break;
+        default:
+            pybind11_fail("invalid evaluation mode");
+    }
+
+    int closeFile = 1;
+    std::string fname_str = (std::string) fname;
+    FILE *f = _Py_fopen_obj(fname.ptr(), "r");
+    if (!f) {
+        PyErr_Clear();
+        pybind11_fail("File \"" + fname_str + "\" could not be opened!");
+    }
+
+    if (!global.contains("__file__")) {
+        global["__file__"] = std::move(fname);
+    }
+
+    PyObject *result
+        = PyRun_FileEx(f, fname_str.c_str(), start, global.ptr(), local.ptr(), closeFile);
+
+    if (!result) {
+        throw error_already_set();
+    }
+    return reinterpret_steal<object>(result);
+}
+#endif
+
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

third-party/DPVO/DPViewer/pybind11/include/pybind11/functional.h

@@ -0,0 +1,130 @@
+/*
+    pybind11/functional.h: std::function<> support
+
+    Copyright (c) 2016 Wenzel Jakob <[email protected]>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "pybind11.h"
+
+#include <functional>
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+template <typename Return, typename... Args>
+struct type_caster<std::function<Return(Args...)>> {
+    using type = std::function<Return(Args...)>;
+    using retval_type = conditional_t<std::is_same<Return, void>::value, void_type, Return>;
+    using function_type = Return (*)(Args...);
+
+public:
+    bool load(handle src, bool convert) {
+        if (src.is_none()) {
+            // Defer accepting None to other overloads (if we aren't in convert mode):
+            if (!convert) {
+                return false;
+            }
+            return true;
+        }
+
+        if (!isinstance<function>(src)) {
+            return false;
+        }
+
+        auto func = reinterpret_borrow<function>(src);
+
+        /*
+           When passing a C++ function as an argument to another C++
+           function via Python, every function call would normally involve
+           a full C++ -> Python -> C++ roundtrip, which can be prohibitive.
+           Here, we try to at least detect the case where the function is
+           stateless (i.e. function pointer or lambda function without
+           captured variables), in which case the roundtrip can be avoided.
+         */
+        if (auto cfunc = func.cpp_function()) {
+            auto *cfunc_self = PyCFunction_GET_SELF(cfunc.ptr());
+            if (isinstance<capsule>(cfunc_self)) {
+                auto c = reinterpret_borrow<capsule>(cfunc_self);
+                auto *rec = (function_record *) c;
+
+                while (rec != nullptr) {
+                    if (rec->is_stateless
+                        && same_type(typeid(function_type),
+                                     *reinterpret_cast<const std::type_info *>(rec->data[1]))) {
+                        struct capture {
+                            function_type f;
+                        };
+                        value = ((capture *) &rec->data)->f;
+                        return true;
+                    }
+                    rec = rec->next;
+                }
+            }
+            // PYPY segfaults here when passing builtin function like sum.
+            // Raising an fail exception here works to prevent the segfault, but only on gcc.
+            // See PR #1413 for full details
+        }
+
+        // ensure GIL is held during functor destruction
+        struct func_handle {
+            function f;
+#if !(defined(_MSC_VER) && _MSC_VER == 1916 && defined(PYBIND11_CPP17))
+            // This triggers a syntax error under very special conditions (very weird indeed).
+            explicit
+#endif
+                func_handle(function &&f_) noexcept
+                : f(std::move(f_)) {
+            }
+            func_handle(const func_handle &f_) { operator=(f_); }
+            func_handle &operator=(const func_handle &f_) {
+                gil_scoped_acquire acq;
+                f = f_.f;
+                return *this;
+            }
+            ~func_handle() {
+                gil_scoped_acquire acq;
+                function kill_f(std::move(f));
+            }
+        };
+
+        // to emulate 'move initialization capture' in C++11
+        struct func_wrapper {
+            func_handle hfunc;
+            explicit func_wrapper(func_handle &&hf) noexcept : hfunc(std::move(hf)) {}
+            Return operator()(Args... args) const {
+                gil_scoped_acquire acq;
+                // casts the returned object as a rvalue to the return type
+                return hfunc.f(std::forward<Args>(args)...).template cast<Return>();
+            }
+        };
+
+        value = func_wrapper(func_handle(std::move(func)));
+        return true;
+    }
+
+    template <typename Func>
+    static handle cast(Func &&f_, return_value_policy policy, handle /* parent */) {
+        if (!f_) {
+            return none().inc_ref();
+        }
+
+        auto result = f_.template target<function_type>();
+        if (result) {
+            return cpp_function(*result, policy).release();
+        }
+        return cpp_function(std::forward<Func>(f_), policy).release();
+    }
+
+    PYBIND11_TYPE_CASTER(type,
+                         const_name("Callable[[") + concat(make_caster<Args>::name...)
+                             + const_name("], ") + make_caster<retval_type>::name
+                             + const_name("]"));
+};
+
+PYBIND11_NAMESPACE_END(detail)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

third-party/DPVO/DPViewer/pybind11/include/pybind11/gil.h

@@ -0,0 +1,202 @@
+/*
+    pybind11/gil.h: RAII helpers for managing the GIL
+
+    Copyright (c) 2016 Wenzel Jakob <[email protected]>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "detail/common.h"
+#include "detail/internals.h"
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+// forward declarations
+PyThreadState *get_thread_state_unchecked();
+
+PYBIND11_NAMESPACE_END(detail)
+
+#if defined(WITH_THREAD) && !defined(PYPY_VERSION)
+
+/* The functions below essentially reproduce the PyGILState_* API using a RAII
+ * pattern, but there are a few important differences:
+ *
+ * 1. When acquiring the GIL from an non-main thread during the finalization
+ *    phase, the GILState API blindly terminates the calling thread, which
+ *    is often not what is wanted. This API does not do this.
+ *
+ * 2. The gil_scoped_release function can optionally cut the relationship
+ *    of a PyThreadState and its associated thread, which allows moving it to
+ *    another thread (this is a fairly rare/advanced use case).
+ *
+ * 3. The reference count of an acquired thread state can be controlled. This
+ *    can be handy to prevent cases where callbacks issued from an external
+ *    thread would otherwise constantly construct and destroy thread state data
+ *    structures.
+ *
+ * See the Python bindings of NanoGUI (http://github.com/wjakob/nanogui) for an
+ * example which uses features 2 and 3 to migrate the Python thread of
+ * execution to another thread (to run the event loop on the original thread,
+ * in this case).
+ */
+
+class gil_scoped_acquire {
+public:
+    PYBIND11_NOINLINE gil_scoped_acquire() {
+        auto &internals = detail::get_internals();
+        tstate = (PyThreadState *) PYBIND11_TLS_GET_VALUE(internals.tstate);
+
+        if (!tstate) {
+            /* Check if the GIL was acquired using the PyGILState_* API instead (e.g. if
+               calling from a Python thread). Since we use a different key, this ensures
+               we don't create a new thread state and deadlock in PyEval_AcquireThread
+               below. Note we don't save this state with internals.tstate, since we don't
+               create it we would fail to clear it (its reference count should be > 0). */
+            tstate = PyGILState_GetThisThreadState();
+        }
+
+        if (!tstate) {
+            tstate = PyThreadState_New(internals.istate);
+#    if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
+            if (!tstate) {
+                pybind11_fail("scoped_acquire: could not create thread state!");
+            }
+#    endif
+            tstate->gilstate_counter = 0;
+            PYBIND11_TLS_REPLACE_VALUE(internals.tstate, tstate);
+        } else {
+            release = detail::get_thread_state_unchecked() != tstate;
+        }
+
+        if (release) {
+            PyEval_AcquireThread(tstate);
+        }
+
+        inc_ref();
+    }
+
+    void inc_ref() { ++tstate->gilstate_counter; }
+
+    PYBIND11_NOINLINE void dec_ref() {
+        --tstate->gilstate_counter;
+#    if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
+        if (detail::get_thread_state_unchecked() != tstate) {
+            pybind11_fail("scoped_acquire::dec_ref(): thread state must be current!");
+        }
+        if (tstate->gilstate_counter < 0) {
+            pybind11_fail("scoped_acquire::dec_ref(): reference count underflow!");
+        }
+#    endif
+        if (tstate->gilstate_counter == 0) {
+#    if defined(PYBIND11_DETAILED_ERROR_MESSAGES)
+            if (!release) {
+                pybind11_fail("scoped_acquire::dec_ref(): internal error!");
+            }
+#    endif
+            PyThreadState_Clear(tstate);
+            if (active) {
+                PyThreadState_DeleteCurrent();
+            }
+            PYBIND11_TLS_DELETE_VALUE(detail::get_internals().tstate);
+            release = false;
+        }
+    }
+
+    /// This method will disable the PyThreadState_DeleteCurrent call and the
+    /// GIL won't be acquired. This method should be used if the interpreter
+    /// could be shutting down when this is called, as thread deletion is not
+    /// allowed during shutdown. Check _Py_IsFinalizing() on Python 3.7+, and
+    /// protect subsequent code.
+    PYBIND11_NOINLINE void disarm() { active = false; }
+
+    PYBIND11_NOINLINE ~gil_scoped_acquire() {
+        dec_ref();
+        if (release) {
+            PyEval_SaveThread();
+        }
+    }
+
+private:
+    PyThreadState *tstate = nullptr;
+    bool release = true;
+    bool active = true;
+};
+
+class gil_scoped_release {
+public:
+    explicit gil_scoped_release(bool disassoc = false) : disassoc(disassoc) {
+        // `get_internals()` must be called here unconditionally in order to initialize
+        // `internals.tstate` for subsequent `gil_scoped_acquire` calls. Otherwise, an
+        // initialization race could occur as multiple threads try `gil_scoped_acquire`.
+        auto &internals = detail::get_internals();
+        // NOLINTNEXTLINE(cppcoreguidelines-prefer-member-initializer)
+        tstate = PyEval_SaveThread();
+        if (disassoc) {
+            // Python >= 3.7 can remove this, it's an int before 3.7
+            // NOLINTNEXTLINE(readability-qualified-auto)
+            auto key = internals.tstate;
+            PYBIND11_TLS_DELETE_VALUE(key);
+        }
+    }
+
+    /// This method will disable the PyThreadState_DeleteCurrent call and the
+    /// GIL won't be acquired. This method should be used if the interpreter
+    /// could be shutting down when this is called, as thread deletion is not
+    /// allowed during shutdown. Check _Py_IsFinalizing() on Python 3.7+, and
+    /// protect subsequent code.
+    PYBIND11_NOINLINE void disarm() { active = false; }
+
+    ~gil_scoped_release() {
+        if (!tstate) {
+            return;
+        }
+        // `PyEval_RestoreThread()` should not be called if runtime is finalizing
+        if (active) {
+            PyEval_RestoreThread(tstate);
+        }
+        if (disassoc) {
+            // Python >= 3.7 can remove this, it's an int before 3.7
+            // NOLINTNEXTLINE(readability-qualified-auto)
+            auto key = detail::get_internals().tstate;
+            PYBIND11_TLS_REPLACE_VALUE(key, tstate);
+        }
+    }
+
+private:
+    PyThreadState *tstate;
+    bool disassoc;
+    bool active = true;
+};
+#elif defined(PYPY_VERSION)
+class gil_scoped_acquire {
+    PyGILState_STATE state;
+
+public:
+    gil_scoped_acquire() { state = PyGILState_Ensure(); }
+    ~gil_scoped_acquire() { PyGILState_Release(state); }
+    void disarm() {}
+};
+
+class gil_scoped_release {
+    PyThreadState *state;
+
+public:
+    gil_scoped_release() { state = PyEval_SaveThread(); }
+    ~gil_scoped_release() { PyEval_RestoreThread(state); }
+    void disarm() {}
+};
+#else
+class gil_scoped_acquire {
+    void disarm() {}
+};
+class gil_scoped_release {
+    void disarm() {}
+};
+#endif
+
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

third-party/DPVO/DPViewer/pybind11/include/pybind11/iostream.h

@@ -0,0 +1,265 @@
+/*
+    pybind11/iostream.h -- Tools to assist with redirecting cout and cerr to Python
+
+    Copyright (c) 2017 Henry F. Schreiner
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+
+    WARNING: The implementation in this file is NOT thread safe. Multiple
+    threads writing to a redirected ostream concurrently cause data races
+    and potentially buffer overflows. Therefore it is currently a requirement
+    that all (possibly) concurrent redirected ostream writes are protected by
+    a mutex.
+    #HelpAppreciated: Work on iostream.h thread safety.
+    For more background see the discussions under
+    https://github.com/pybind/pybind11/pull/2982 and
+    https://github.com/pybind/pybind11/pull/2995.
+*/
+
+#pragma once
+
+#include "pybind11.h"
+
+#include <algorithm>
+#include <cstring>
+#include <iostream>
+#include <iterator>
+#include <memory>
+#include <ostream>
+#include <streambuf>
+#include <string>
+#include <utility>
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+// Buffer that writes to Python instead of C++
+class pythonbuf : public std::streambuf {
+private:
+    using traits_type = std::streambuf::traits_type;
+
+    const size_t buf_size;
+    std::unique_ptr<char[]> d_buffer;
+    object pywrite;
+    object pyflush;
+
+    int overflow(int c) override {
+        if (!traits_type::eq_int_type(c, traits_type::eof())) {
+            *pptr() = traits_type::to_char_type(c);
+            pbump(1);
+        }
+        return sync() == 0 ? traits_type::not_eof(c) : traits_type::eof();
+    }
+
+    // Computes how many bytes at the end of the buffer are part of an
+    // incomplete sequence of UTF-8 bytes.
+    // Precondition: pbase() < pptr()
+    size_t utf8_remainder() const {
+        const auto rbase = std::reverse_iterator<char *>(pbase());
+        const auto rpptr = std::reverse_iterator<char *>(pptr());
+        auto is_ascii = [](char c) { return (static_cast<unsigned char>(c) & 0x80) == 0x00; };
+        auto is_leading = [](char c) { return (static_cast<unsigned char>(c) & 0xC0) == 0xC0; };
+        auto is_leading_2b = [](char c) { return static_cast<unsigned char>(c) <= 0xDF; };
+        auto is_leading_3b = [](char c) { return static_cast<unsigned char>(c) <= 0xEF; };
+        // If the last character is ASCII, there are no incomplete code points
+        if (is_ascii(*rpptr)) {
+            return 0;
+        }
+        // Otherwise, work back from the end of the buffer and find the first
+        // UTF-8 leading byte
+        const auto rpend = rbase - rpptr >= 3 ? rpptr + 3 : rbase;
+        const auto leading = std::find_if(rpptr, rpend, is_leading);
+        if (leading == rbase) {
+            return 0;
+        }
+        const auto dist = static_cast<size_t>(leading - rpptr);
+        size_t remainder = 0;
+
+        if (dist == 0) {
+            remainder = 1; // 1-byte code point is impossible
+        } else if (dist == 1) {
+            remainder = is_leading_2b(*leading) ? 0 : dist + 1;
+        } else if (dist == 2) {
+            remainder = is_leading_3b(*leading) ? 0 : dist + 1;
+        }
+        // else if (dist >= 3), at least 4 bytes before encountering an UTF-8
+        // leading byte, either no remainder or invalid UTF-8.
+        // Invalid UTF-8 will cause an exception later when converting
+        // to a Python string, so that's not handled here.
+        return remainder;
+    }
+
+    // This function must be non-virtual to be called in a destructor.
+    int _sync() {
+        if (pbase() != pptr()) { // If buffer is not empty
+            gil_scoped_acquire tmp;
+            // This subtraction cannot be negative, so dropping the sign.
+            auto size = static_cast<size_t>(pptr() - pbase());
+            size_t remainder = utf8_remainder();
+
+            if (size > remainder) {
+                str line(pbase(), size - remainder);
+                pywrite(std::move(line));
+                pyflush();
+            }
+
+            // Copy the remainder at the end of the buffer to the beginning:
+            if (remainder > 0) {
+                std::memmove(pbase(), pptr() - remainder, remainder);
+            }
+            setp(pbase(), epptr());
+            pbump(static_cast<int>(remainder));
+        }
+        return 0;
+    }
+
+    int sync() override { return _sync(); }
+
+public:
+    explicit pythonbuf(const object &pyostream, size_t buffer_size = 1024)
+        : buf_size(buffer_size), d_buffer(new char[buf_size]), pywrite(pyostream.attr("write")),
+          pyflush(pyostream.attr("flush")) {
+        setp(d_buffer.get(), d_buffer.get() + buf_size - 1);
+    }
+
+    pythonbuf(pythonbuf &&) = default;
+
+    /// Sync before destroy
+    ~pythonbuf() override { _sync(); }
+};
+
+PYBIND11_NAMESPACE_END(detail)
+
+/** \rst
+    This a move-only guard that redirects output.
+
+    .. code-block:: cpp
+
+        #include <pybind11/iostream.h>
+
+        ...
+
+        {
+            py::scoped_ostream_redirect output;
+            std::cout << "Hello, World!"; // Python stdout
+        } // <-- return std::cout to normal
+
+    You can explicitly pass the c++ stream and the python object,
+    for example to guard stderr instead.
+
+    .. code-block:: cpp
+
+        {
+            py::scoped_ostream_redirect output{
+                std::cerr, py::module::import("sys").attr("stderr")};
+            std::cout << "Hello, World!";
+        }
+ \endrst */
+class scoped_ostream_redirect {
+protected:
+    std::streambuf *old;
+    std::ostream &costream;
+    detail::pythonbuf buffer;
+
+public:
+    explicit scoped_ostream_redirect(std::ostream &costream = std::cout,
+                                     const object &pyostream
+                                     = module_::import("sys").attr("stdout"))
+        : costream(costream), buffer(pyostream) {
+        old = costream.rdbuf(&buffer);
+    }
+
+    ~scoped_ostream_redirect() { costream.rdbuf(old); }
+
+    scoped_ostream_redirect(const scoped_ostream_redirect &) = delete;
+    scoped_ostream_redirect(scoped_ostream_redirect &&other) = default;
+    scoped_ostream_redirect &operator=(const scoped_ostream_redirect &) = delete;
+    scoped_ostream_redirect &operator=(scoped_ostream_redirect &&) = delete;
+};
+
+/** \rst
+    Like `scoped_ostream_redirect`, but redirects cerr by default. This class
+    is provided primary to make ``py::call_guard`` easier to make.
+
+    .. code-block:: cpp
+
+     m.def("noisy_func", &noisy_func,
+           py::call_guard<scoped_ostream_redirect,
+                          scoped_estream_redirect>());
+
+\endrst */
+class scoped_estream_redirect : public scoped_ostream_redirect {
+public:
+    explicit scoped_estream_redirect(std::ostream &costream = std::cerr,
+                                     const object &pyostream
+                                     = module_::import("sys").attr("stderr"))
+        : scoped_ostream_redirect(costream, pyostream) {}
+};
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+// Class to redirect output as a context manager. C++ backend.
+class OstreamRedirect {
+    bool do_stdout_;
+    bool do_stderr_;
+    std::unique_ptr<scoped_ostream_redirect> redirect_stdout;
+    std::unique_ptr<scoped_estream_redirect> redirect_stderr;
+
+public:
+    explicit OstreamRedirect(bool do_stdout = true, bool do_stderr = true)
+        : do_stdout_(do_stdout), do_stderr_(do_stderr) {}
+
+    void enter() {
+        if (do_stdout_) {
+            redirect_stdout.reset(new scoped_ostream_redirect());
+        }
+        if (do_stderr_) {
+            redirect_stderr.reset(new scoped_estream_redirect());
+        }
+    }
+
+    void exit() {
+        redirect_stdout.reset();
+        redirect_stderr.reset();
+    }
+};
+
+PYBIND11_NAMESPACE_END(detail)
+
+/** \rst
+    This is a helper function to add a C++ redirect context manager to Python
+    instead of using a C++ guard. To use it, add the following to your binding code:
+
+    .. code-block:: cpp
+
+        #include <pybind11/iostream.h>
+
+        ...
+
+        py::add_ostream_redirect(m, "ostream_redirect");
+
+    You now have a Python context manager that redirects your output:
+
+    .. code-block:: python
+
+        with m.ostream_redirect():
+            m.print_to_cout_function()
+
+    This manager can optionally be told which streams to operate on:
+
+    .. code-block:: python
+
+        with m.ostream_redirect(stdout=true, stderr=true):
+            m.noisy_function_with_error_printing()
+
+ \endrst */
+inline class_<detail::OstreamRedirect>
+add_ostream_redirect(module_ m, const std::string &name = "ostream_redirect") {
+    return class_<detail::OstreamRedirect>(std::move(m), name.c_str(), module_local())
+        .def(init<bool, bool>(), arg("stdout") = true, arg("stderr") = true)
+        .def("__enter__", &detail::OstreamRedirect::enter)
+        .def("__exit__", [](detail::OstreamRedirect &self_, const args &) { self_.exit(); });
+}
+
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

third-party/DPVO/DPViewer/pybind11/include/pybind11/numpy.h

@@ -0,0 +1,1984 @@
+/*
+    pybind11/numpy.h: Basic NumPy support, vectorize() wrapper
+
+    Copyright (c) 2016 Wenzel Jakob <[email protected]>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "pybind11.h"
+#include "complex.h"
+
+#include <algorithm>
+#include <array>
+#include <cstdint>
+#include <cstdlib>
+#include <cstring>
+#include <functional>
+#include <numeric>
+#include <sstream>
+#include <string>
+#include <type_traits>
+#include <typeindex>
+#include <utility>
+#include <vector>
+
+/* This will be true on all flat address space platforms and allows us to reduce the
+   whole npy_intp / ssize_t / Py_intptr_t business down to just ssize_t for all size
+   and dimension types (e.g. shape, strides, indexing), instead of inflicting this
+   upon the library user. */
+static_assert(sizeof(::pybind11::ssize_t) == sizeof(Py_intptr_t), "ssize_t != Py_intptr_t");
+static_assert(std::is_signed<Py_intptr_t>::value, "Py_intptr_t must be signed");
+// We now can reinterpret_cast between py::ssize_t and Py_intptr_t (MSVC + PyPy cares)
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+
+class array; // Forward declaration
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+template <>
+struct handle_type_name<array> {
+    static constexpr auto name = const_name("numpy.ndarray");
+};
+
+template <typename type, typename SFINAE = void>
+struct npy_format_descriptor;
+
+struct PyArrayDescr_Proxy {
+    PyObject_HEAD
+    PyObject *typeobj;
+    char kind;
+    char type;
+    char byteorder;
+    char flags;
+    int type_num;
+    int elsize;
+    int alignment;
+    char *subarray;
+    PyObject *fields;
+    PyObject *names;
+};
+
+struct PyArray_Proxy {
+    PyObject_HEAD
+    char *data;
+    int nd;
+    ssize_t *dimensions;
+    ssize_t *strides;
+    PyObject *base;
+    PyObject *descr;
+    int flags;
+};
+
+struct PyVoidScalarObject_Proxy {
+    PyObject_VAR_HEAD char *obval;
+    PyArrayDescr_Proxy *descr;
+    int flags;
+    PyObject *base;
+};
+
+struct numpy_type_info {
+    PyObject *dtype_ptr;
+    std::string format_str;
+};
+
+struct numpy_internals {
+    std::unordered_map<std::type_index, numpy_type_info> registered_dtypes;
+
+    numpy_type_info *get_type_info(const std::type_info &tinfo, bool throw_if_missing = true) {
+        auto it = registered_dtypes.find(std::type_index(tinfo));
+        if (it != registered_dtypes.end()) {
+            return &(it->second);
+        }
+        if (throw_if_missing) {
+            pybind11_fail(std::string("NumPy type info missing for ") + tinfo.name());
+        }
+        return nullptr;
+    }
+
+    template <typename T>
+    numpy_type_info *get_type_info(bool throw_if_missing = true) {
+        return get_type_info(typeid(typename std::remove_cv<T>::type), throw_if_missing);
+    }
+};
+
+PYBIND11_NOINLINE void load_numpy_internals(numpy_internals *&ptr) {
+    ptr = &get_or_create_shared_data<numpy_internals>("_numpy_internals");
+}
+
+inline numpy_internals &get_numpy_internals() {
+    static numpy_internals *ptr = nullptr;
+    if (!ptr) {
+        load_numpy_internals(ptr);
+    }
+    return *ptr;
+}
+
+template <typename T>
+struct same_size {
+    template <typename U>
+    using as = bool_constant<sizeof(T) == sizeof(U)>;
+};
+
+template <typename Concrete>
+constexpr int platform_lookup() {
+    return -1;
+}
+
+// Lookup a type according to its size, and return a value corresponding to the NumPy typenum.
+template <typename Concrete, typename T, typename... Ts, typename... Ints>
+constexpr int platform_lookup(int I, Ints... Is) {
+    return sizeof(Concrete) == sizeof(T) ? I : platform_lookup<Concrete, Ts...>(Is...);
+}
+
+struct npy_api {
+    enum constants {
+        NPY_ARRAY_C_CONTIGUOUS_ = 0x0001,
+        NPY_ARRAY_F_CONTIGUOUS_ = 0x0002,
+        NPY_ARRAY_OWNDATA_ = 0x0004,
+        NPY_ARRAY_FORCECAST_ = 0x0010,
+        NPY_ARRAY_ENSUREARRAY_ = 0x0040,
+        NPY_ARRAY_ALIGNED_ = 0x0100,
+        NPY_ARRAY_WRITEABLE_ = 0x0400,
+        NPY_BOOL_ = 0,
+        NPY_BYTE_,
+        NPY_UBYTE_,
+        NPY_SHORT_,
+        NPY_USHORT_,
+        NPY_INT_,
+        NPY_UINT_,
+        NPY_LONG_,
+        NPY_ULONG_,
+        NPY_LONGLONG_,
+        NPY_ULONGLONG_,
+        NPY_FLOAT_,
+        NPY_DOUBLE_,
+        NPY_LONGDOUBLE_,
+        NPY_CFLOAT_,
+        NPY_CDOUBLE_,
+        NPY_CLONGDOUBLE_,
+        NPY_OBJECT_ = 17,
+        NPY_STRING_,
+        NPY_UNICODE_,
+        NPY_VOID_,
+        // Platform-dependent normalization
+        NPY_INT8_ = NPY_BYTE_,
+        NPY_UINT8_ = NPY_UBYTE_,
+        NPY_INT16_ = NPY_SHORT_,
+        NPY_UINT16_ = NPY_USHORT_,
+        // `npy_common.h` defines the integer aliases. In order, it checks:
+        // NPY_BITSOF_LONG, NPY_BITSOF_LONGLONG, NPY_BITSOF_INT, NPY_BITSOF_SHORT, NPY_BITSOF_CHAR
+        // and assigns the alias to the first matching size, so we should check in this order.
+        NPY_INT32_
+        = platform_lookup<std::int32_t, long, int, short>(NPY_LONG_, NPY_INT_, NPY_SHORT_),
+        NPY_UINT32_ = platform_lookup<std::uint32_t, unsigned long, unsigned int, unsigned short>(
+            NPY_ULONG_, NPY_UINT_, NPY_USHORT_),
+        NPY_INT64_
+        = platform_lookup<std::int64_t, long, long long, int>(NPY_LONG_, NPY_LONGLONG_, NPY_INT_),
+        NPY_UINT64_
+        = platform_lookup<std::uint64_t, unsigned long, unsigned long long, unsigned int>(
+            NPY_ULONG_, NPY_ULONGLONG_, NPY_UINT_),
+    };
+
+    struct PyArray_Dims {
+        Py_intptr_t *ptr;
+        int len;
+    };
+
+    static npy_api &get() {
+        static npy_api api = lookup();
+        return api;
+    }
+
+    bool PyArray_Check_(PyObject *obj) const {
+        return PyObject_TypeCheck(obj, PyArray_Type_) != 0;
+    }
+    bool PyArrayDescr_Check_(PyObject *obj) const {
+        return PyObject_TypeCheck(obj, PyArrayDescr_Type_) != 0;
+    }
+
+    unsigned int (*PyArray_GetNDArrayCFeatureVersion_)();
+    PyObject *(*PyArray_DescrFromType_)(int);
+    PyObject *(*PyArray_NewFromDescr_)(PyTypeObject *,
+                                       PyObject *,
+                                       int,
+                                       Py_intptr_t const *,
+                                       Py_intptr_t const *,
+                                       void *,
+                                       int,
+                                       PyObject *);
+    // Unused. Not removed because that affects ABI of the class.
+    PyObject *(*PyArray_DescrNewFromType_)(int);
+    int (*PyArray_CopyInto_)(PyObject *, PyObject *);
+    PyObject *(*PyArray_NewCopy_)(PyObject *, int);
+    PyTypeObject *PyArray_Type_;
+    PyTypeObject *PyVoidArrType_Type_;
+    PyTypeObject *PyArrayDescr_Type_;
+    PyObject *(*PyArray_DescrFromScalar_)(PyObject *);
+    PyObject *(*PyArray_FromAny_)(PyObject *, PyObject *, int, int, int, PyObject *);
+    int (*PyArray_DescrConverter_)(PyObject *, PyObject **);
+    bool (*PyArray_EquivTypes_)(PyObject *, PyObject *);
+    int (*PyArray_GetArrayParamsFromObject_)(PyObject *,
+                                             PyObject *,
+                                             unsigned char,
+                                             PyObject **,
+                                             int *,
+                                             Py_intptr_t *,
+                                             PyObject **,
+                                             PyObject *);
+    PyObject *(*PyArray_Squeeze_)(PyObject *);
+    // Unused. Not removed because that affects ABI of the class.
+    int (*PyArray_SetBaseObject_)(PyObject *, PyObject *);
+    PyObject *(*PyArray_Resize_)(PyObject *, PyArray_Dims *, int, int);
+    PyObject *(*PyArray_Newshape_)(PyObject *, PyArray_Dims *, int);
+    PyObject *(*PyArray_View_)(PyObject *, PyObject *, PyObject *);
+
+private:
+    enum functions {
+        API_PyArray_GetNDArrayCFeatureVersion = 211,
+        API_PyArray_Type = 2,
+        API_PyArrayDescr_Type = 3,
+        API_PyVoidArrType_Type = 39,
+        API_PyArray_DescrFromType = 45,
+        API_PyArray_DescrFromScalar = 57,
+        API_PyArray_FromAny = 69,
+        API_PyArray_Resize = 80,
+        API_PyArray_CopyInto = 82,
+        API_PyArray_NewCopy = 85,
+        API_PyArray_NewFromDescr = 94,
+        API_PyArray_DescrNewFromType = 96,
+        API_PyArray_Newshape = 135,
+        API_PyArray_Squeeze = 136,
+        API_PyArray_View = 137,
+        API_PyArray_DescrConverter = 174,
+        API_PyArray_EquivTypes = 182,
+        API_PyArray_GetArrayParamsFromObject = 278,
+        API_PyArray_SetBaseObject = 282
+    };
+
+    static npy_api lookup() {
+        module_ m = module_::import("numpy.core.multiarray");
+        auto c = m.attr("_ARRAY_API");
+        void **api_ptr = (void **) PyCapsule_GetPointer(c.ptr(), nullptr);
+        npy_api api;
+#define DECL_NPY_API(Func) api.Func##_ = (decltype(api.Func##_)) api_ptr[API_##Func];
+        DECL_NPY_API(PyArray_GetNDArrayCFeatureVersion);
+        if (api.PyArray_GetNDArrayCFeatureVersion_() < 0x7) {
+            pybind11_fail("pybind11 numpy support requires numpy >= 1.7.0");
+        }
+        DECL_NPY_API(PyArray_Type);
+        DECL_NPY_API(PyVoidArrType_Type);
+        DECL_NPY_API(PyArrayDescr_Type);
+        DECL_NPY_API(PyArray_DescrFromType);
+        DECL_NPY_API(PyArray_DescrFromScalar);
+        DECL_NPY_API(PyArray_FromAny);
+        DECL_NPY_API(PyArray_Resize);
+        DECL_NPY_API(PyArray_CopyInto);
+        DECL_NPY_API(PyArray_NewCopy);
+        DECL_NPY_API(PyArray_NewFromDescr);
+        DECL_NPY_API(PyArray_DescrNewFromType);
+        DECL_NPY_API(PyArray_Newshape);
+        DECL_NPY_API(PyArray_Squeeze);
+        DECL_NPY_API(PyArray_View);
+        DECL_NPY_API(PyArray_DescrConverter);
+        DECL_NPY_API(PyArray_EquivTypes);
+        DECL_NPY_API(PyArray_GetArrayParamsFromObject);
+        DECL_NPY_API(PyArray_SetBaseObject);
+
+#undef DECL_NPY_API
+        return api;
+    }
+};
+
+inline PyArray_Proxy *array_proxy(void *ptr) { return reinterpret_cast<PyArray_Proxy *>(ptr); }
+
+inline const PyArray_Proxy *array_proxy(const void *ptr) {
+    return reinterpret_cast<const PyArray_Proxy *>(ptr);
+}
+
+inline PyArrayDescr_Proxy *array_descriptor_proxy(PyObject *ptr) {
+    return reinterpret_cast<PyArrayDescr_Proxy *>(ptr);
+}
+
+inline const PyArrayDescr_Proxy *array_descriptor_proxy(const PyObject *ptr) {
+    return reinterpret_cast<const PyArrayDescr_Proxy *>(ptr);
+}
+
+inline bool check_flags(const void *ptr, int flag) {
+    return (flag == (array_proxy(ptr)->flags & flag));
+}
+
+template <typename T>
+struct is_std_array : std::false_type {};
+template <typename T, size_t N>
+struct is_std_array<std::array<T, N>> : std::true_type {};
+template <typename T>
+struct is_complex : std::false_type {};
+template <typename T>
+struct is_complex<std::complex<T>> : std::true_type {};
+
+template <typename T>
+struct array_info_scalar {
+    using type = T;
+    static constexpr bool is_array = false;
+    static constexpr bool is_empty = false;
+    static constexpr auto extents = const_name("");
+    static void append_extents(list & /* shape */) {}
+};
+// Computes underlying type and a comma-separated list of extents for array
+// types (any mix of std::array and built-in arrays). An array of char is
+// treated as scalar because it gets special handling.
+template <typename T>
+struct array_info : array_info_scalar<T> {};
+template <typename T, size_t N>
+struct array_info<std::array<T, N>> {
+    using type = typename array_info<T>::type;
+    static constexpr bool is_array = true;
+    static constexpr bool is_empty = (N == 0) || array_info<T>::is_empty;
+    static constexpr size_t extent = N;
+
+    // appends the extents to shape
+    static void append_extents(list &shape) {
+        shape.append(N);
+        array_info<T>::append_extents(shape);
+    }
+
+    static constexpr auto extents = const_name<array_info<T>::is_array>(
+        concat(const_name<N>(), array_info<T>::extents), const_name<N>());
+};
+// For numpy we have special handling for arrays of characters, so we don't include
+// the size in the array extents.
+template <size_t N>
+struct array_info<char[N]> : array_info_scalar<char[N]> {};
+template <size_t N>
+struct array_info<std::array<char, N>> : array_info_scalar<std::array<char, N>> {};
+template <typename T, size_t N>
+struct array_info<T[N]> : array_info<std::array<T, N>> {};
+template <typename T>
+using remove_all_extents_t = typename array_info<T>::type;
+
+template <typename T>
+using is_pod_struct
+    = all_of<std::is_standard_layout<T>, // since we're accessing directly in memory
+                                         // we need a standard layout type
+#if defined(__GLIBCXX__)                                                                          \
+    && (__GLIBCXX__ < 20150422 || __GLIBCXX__ == 20150426 || __GLIBCXX__ == 20150623              \
+        || __GLIBCXX__ == 20150626 || __GLIBCXX__ == 20160803)
+             // libstdc++ < 5 (including versions 4.8.5, 4.9.3 and 4.9.4 which were released after
+             // 5) don't implement is_trivially_copyable, so approximate it
+             std::is_trivially_destructible<T>,
+             satisfies_any_of<T, std::has_trivial_copy_constructor, std::has_trivial_copy_assign>,
+#else
+             std::is_trivially_copyable<T>,
+#endif
+             satisfies_none_of<T,
+                               std::is_reference,
+                               std::is_array,
+                               is_std_array,
+                               std::is_arithmetic,
+                               is_complex,
+                               std::is_enum>>;
+
+// Replacement for std::is_pod (deprecated in C++20)
+template <typename T>
+using is_pod = all_of<std::is_standard_layout<T>, std::is_trivial<T>>;
+
+template <ssize_t Dim = 0, typename Strides>
+ssize_t byte_offset_unsafe(const Strides &) {
+    return 0;
+}
+template <ssize_t Dim = 0, typename Strides, typename... Ix>
+ssize_t byte_offset_unsafe(const Strides &strides, ssize_t i, Ix... index) {
+    return i * strides[Dim] + byte_offset_unsafe<Dim + 1>(strides, index...);
+}
+
+/**
+ * Proxy class providing unsafe, unchecked const access to array data.  This is constructed through
+ * the `unchecked<T, N>()` method of `array` or the `unchecked<N>()` method of `array_t<T>`. `Dims`
+ * will be -1 for dimensions determined at runtime.
+ */
+template <typename T, ssize_t Dims>
+class unchecked_reference {
+protected:
+    static constexpr bool Dynamic = Dims < 0;
+    const unsigned char *data_;
+    // Storing the shape & strides in local variables (i.e. these arrays) allows the compiler to
+    // make large performance gains on big, nested loops, but requires compile-time dimensions
+    conditional_t<Dynamic, const ssize_t *, std::array<ssize_t, (size_t) Dims>> shape_, strides_;
+    const ssize_t dims_;
+
+    friend class pybind11::array;
+    // Constructor for compile-time dimensions:
+    template <bool Dyn = Dynamic>
+    unchecked_reference(const void *data,
+                        const ssize_t *shape,
+                        const ssize_t *strides,
+                        enable_if_t<!Dyn, ssize_t>)
+        : data_{reinterpret_cast<const unsigned char *>(data)}, dims_{Dims} {
+        for (size_t i = 0; i < (size_t) dims_; i++) {
+            shape_[i] = shape[i];
+            strides_[i] = strides[i];
+        }
+    }
+    // Constructor for runtime dimensions:
+    template <bool Dyn = Dynamic>
+    unchecked_reference(const void *data,
+                        const ssize_t *shape,
+                        const ssize_t *strides,
+                        enable_if_t<Dyn, ssize_t> dims)
+        : data_{reinterpret_cast<const unsigned char *>(data)}, shape_{shape}, strides_{strides},
+          dims_{dims} {}
+
+public:
+    /**
+     * Unchecked const reference access to data at the given indices.  For a compile-time known
+     * number of dimensions, this requires the correct number of arguments; for run-time
+     * dimensionality, this is not checked (and so is up to the caller to use safely).
+     */
+    template <typename... Ix>
+    const T &operator()(Ix... index) const {
+        static_assert(ssize_t{sizeof...(Ix)} == Dims || Dynamic,
+                      "Invalid number of indices for unchecked array reference");
+        return *reinterpret_cast<const T *>(data_
+                                            + byte_offset_unsafe(strides_, ssize_t(index)...));
+    }
+    /**
+     * Unchecked const reference access to data; this operator only participates if the reference
+     * is to a 1-dimensional array.  When present, this is exactly equivalent to `obj(index)`.
+     */
+    template <ssize_t D = Dims, typename = enable_if_t<D == 1 || Dynamic>>
+    const T &operator[](ssize_t index) const {
+        return operator()(index);
+    }
+
+    /// Pointer access to the data at the given indices.
+    template <typename... Ix>
+    const T *data(Ix... ix) const {
+        return &operator()(ssize_t(ix)...);
+    }
+
+    /// Returns the item size, i.e. sizeof(T)
+    constexpr static ssize_t itemsize() { return sizeof(T); }
+
+    /// Returns the shape (i.e. size) of dimension `dim`
+    ssize_t shape(ssize_t dim) const { return shape_[(size_t) dim]; }
+
+    /// Returns the number of dimensions of the array
+    ssize_t ndim() const { return dims_; }
+
+    /// Returns the total number of elements in the referenced array, i.e. the product of the
+    /// shapes
+    template <bool Dyn = Dynamic>
+    enable_if_t<!Dyn, ssize_t> size() const {
+        return std::accumulate(
+            shape_.begin(), shape_.end(), (ssize_t) 1, std::multiplies<ssize_t>());
+    }
+    template <bool Dyn = Dynamic>
+    enable_if_t<Dyn, ssize_t> size() const {
+        return std::accumulate(shape_, shape_ + ndim(), (ssize_t) 1, std::multiplies<ssize_t>());
+    }
+
+    /// Returns the total number of bytes used by the referenced data.  Note that the actual span
+    /// in memory may be larger if the referenced array has non-contiguous strides (e.g. for a
+    /// slice).
+    ssize_t nbytes() const { return size() * itemsize(); }
+};
+
+template <typename T, ssize_t Dims>
+class unchecked_mutable_reference : public unchecked_reference<T, Dims> {
+    friend class pybind11::array;
+    using ConstBase = unchecked_reference<T, Dims>;
+    using ConstBase::ConstBase;
+    using ConstBase::Dynamic;
+
+public:
+    // Bring in const-qualified versions from base class
+    using ConstBase::operator();
+    using ConstBase::operator[];
+
+    /// Mutable, unchecked access to data at the given indices.
+    template <typename... Ix>
+    T &operator()(Ix... index) {
+        static_assert(ssize_t{sizeof...(Ix)} == Dims || Dynamic,
+                      "Invalid number of indices for unchecked array reference");
+        return const_cast<T &>(ConstBase::operator()(index...));
+    }
+    /**
+     * Mutable, unchecked access data at the given index; this operator only participates if the
+     * reference is to a 1-dimensional array (or has runtime dimensions).  When present, this is
+     * exactly equivalent to `obj(index)`.
+     */
+    template <ssize_t D = Dims, typename = enable_if_t<D == 1 || Dynamic>>
+    T &operator[](ssize_t index) {
+        return operator()(index);
+    }
+
+    /// Mutable pointer access to the data at the given indices.
+    template <typename... Ix>
+    T *mutable_data(Ix... ix) {
+        return &operator()(ssize_t(ix)...);
+    }
+};
+
+template <typename T, ssize_t Dim>
+struct type_caster<unchecked_reference<T, Dim>> {
+    static_assert(Dim == 0 && Dim > 0 /* always fail */,
+                  "unchecked array proxy object is not castable");
+};
+template <typename T, ssize_t Dim>
+struct type_caster<unchecked_mutable_reference<T, Dim>>
+    : type_caster<unchecked_reference<T, Dim>> {};
+
+PYBIND11_NAMESPACE_END(detail)
+
+class dtype : public object {
+public:
+    PYBIND11_OBJECT_DEFAULT(dtype, object, detail::npy_api::get().PyArrayDescr_Check_);
+
+    explicit dtype(const buffer_info &info) {
+        dtype descr(_dtype_from_pep3118()(pybind11::str(info.format)));
+        // If info.itemsize == 0, use the value calculated from the format string
+        m_ptr = descr.strip_padding(info.itemsize != 0 ? info.itemsize : descr.itemsize())
+                    .release()
+                    .ptr();
+    }
+
+    explicit dtype(const pybind11::str &format) : dtype(from_args(format)) {}
+
+    explicit dtype(const std::string &format) : dtype(pybind11::str(format)) {}
+
+    explicit dtype(const char *format) : dtype(pybind11::str(format)) {}
+
+    dtype(list names, list formats, list offsets, ssize_t itemsize) {
+        dict args;
+        args["names"] = std::move(names);
+        args["formats"] = std::move(formats);
+        args["offsets"] = std::move(offsets);
+        args["itemsize"] = pybind11::int_(itemsize);
+        m_ptr = from_args(args).release().ptr();
+    }
+
+    explicit dtype(int typenum)
+        : object(detail::npy_api::get().PyArray_DescrFromType_(typenum), stolen_t{}) {
+        if (m_ptr == nullptr) {
+            throw error_already_set();
+        }
+    }
+
+    /// This is essentially the same as calling numpy.dtype(args) in Python.
+    static dtype from_args(const object &args) {
+        PyObject *ptr = nullptr;
+        if ((detail::npy_api::get().PyArray_DescrConverter_(args.ptr(), &ptr) == 0) || !ptr) {
+            throw error_already_set();
+        }
+        return reinterpret_steal<dtype>(ptr);
+    }
+
+    /// Return dtype associated with a C++ type.
+    template <typename T>
+    static dtype of() {
+        return detail::npy_format_descriptor<typename std::remove_cv<T>::type>::dtype();
+    }
+
+    /// Size of the data type in bytes.
+    ssize_t itemsize() const { return detail::array_descriptor_proxy(m_ptr)->elsize; }
+
+    /// Returns true for structured data types.
+    bool has_fields() const { return detail::array_descriptor_proxy(m_ptr)->names != nullptr; }
+
+    /// Single-character code for dtype's kind.
+    /// For example, floating point types are 'f' and integral types are 'i'.
+    char kind() const { return detail::array_descriptor_proxy(m_ptr)->kind; }
+
+    /// Single-character for dtype's type.
+    /// For example, ``float`` is 'f', ``double`` 'd', ``int`` 'i', and ``long`` 'l'.
+    char char_() const {
+        // Note: The signature, `dtype::char_` follows the naming of NumPy's
+        // public Python API (i.e., ``dtype.char``), rather than its internal
+        // C API (``PyArray_Descr::type``).
+        return detail::array_descriptor_proxy(m_ptr)->type;
+    }
+
+    /// type number of dtype.
+    int num() const {
+        // Note: The signature, `dtype::num` follows the naming of NumPy's public
+        // Python API (i.e., ``dtype.num``), rather than its internal
+        // C API (``PyArray_Descr::type_num``).
+        return detail::array_descriptor_proxy(m_ptr)->type_num;
+    }
+
+    /// Single character for byteorder
+    char byteorder() const { return detail::array_descriptor_proxy(m_ptr)->byteorder; }
+
+    /// Alignment of the data type
+    int alignment() const { return detail::array_descriptor_proxy(m_ptr)->alignment; }
+
+    /// Flags for the array descriptor
+    char flags() const { return detail::array_descriptor_proxy(m_ptr)->flags; }
+
+private:
+    static object _dtype_from_pep3118() {
+        static PyObject *obj = module_::import("numpy.core._internal")
+                                   .attr("_dtype_from_pep3118")
+                                   .cast<object>()
+                                   .release()
+                                   .ptr();
+        return reinterpret_borrow<object>(obj);
+    }
+
+    dtype strip_padding(ssize_t itemsize) {
+        // Recursively strip all void fields with empty names that are generated for
+        // padding fields (as of NumPy v1.11).
+        if (!has_fields()) {
+            return *this;
+        }
+
+        struct field_descr {
+            pybind11::str name;
+            object format;
+            pybind11::int_ offset;
+            field_descr(pybind11::str &&name, object &&format, pybind11::int_ &&offset)
+                : name{std::move(name)}, format{std::move(format)}, offset{std::move(offset)} {};
+        };
+        auto field_dict = attr("fields").cast<dict>();
+        std::vector<field_descr> field_descriptors;
+        field_descriptors.reserve(field_dict.size());
+
+        for (auto field : field_dict.attr("items")()) {
+            auto spec = field.cast<tuple>();
+            auto name = spec[0].cast<pybind11::str>();
+            auto spec_fo = spec[1].cast<tuple>();
+            auto format = spec_fo[0].cast<dtype>();
+            auto offset = spec_fo[1].cast<pybind11::int_>();
+            if ((len(name) == 0u) && format.kind() == 'V') {
+                continue;
+            }
+            field_descriptors.emplace_back(
+                std::move(name), format.strip_padding(format.itemsize()), std::move(offset));
+        }
+
+        std::sort(field_descriptors.begin(),
+                  field_descriptors.end(),
+                  [](const field_descr &a, const field_descr &b) {
+                      return a.offset.cast<int>() < b.offset.cast<int>();
+                  });
+
+        list names, formats, offsets;
+        for (auto &descr : field_descriptors) {
+            names.append(std::move(descr.name));
+            formats.append(std::move(descr.format));
+            offsets.append(std::move(descr.offset));
+        }
+        return dtype(std::move(names), std::move(formats), std::move(offsets), itemsize);
+    }
+};
+
+class array : public buffer {
+public:
+    PYBIND11_OBJECT_CVT(array, buffer, detail::npy_api::get().PyArray_Check_, raw_array)
+
+    enum {
+        c_style = detail::npy_api::NPY_ARRAY_C_CONTIGUOUS_,
+        f_style = detail::npy_api::NPY_ARRAY_F_CONTIGUOUS_,
+        forcecast = detail::npy_api::NPY_ARRAY_FORCECAST_
+    };
+
+    array() : array(0, static_cast<const double *>(nullptr)) {}
+
+    using ShapeContainer = detail::any_container<ssize_t>;
+    using StridesContainer = detail::any_container<ssize_t>;
+
+    // Constructs an array taking shape/strides from arbitrary container types
+    array(const pybind11::dtype &dt,
+          ShapeContainer shape,
+          StridesContainer strides,
+          const void *ptr = nullptr,
+          handle base = handle()) {
+
+        if (strides->empty()) {
+            *strides = detail::c_strides(*shape, dt.itemsize());
+        }
+
+        auto ndim = shape->size();
+        if (ndim != strides->size()) {
+            pybind11_fail("NumPy: shape ndim doesn't match strides ndim");
+        }
+        auto descr = dt;
+
+        int flags = 0;
+        if (base && ptr) {
+            if (isinstance<array>(base)) {
+                /* Copy flags from base (except ownership bit) */
+                flags = reinterpret_borrow<array>(base).flags()
+                        & ~detail::npy_api::NPY_ARRAY_OWNDATA_;
+            } else {
+                /* Writable by default, easy to downgrade later on if needed */
+                flags = detail::npy_api::NPY_ARRAY_WRITEABLE_;
+            }
+        }
+
+        auto &api = detail::npy_api::get();
+        auto tmp = reinterpret_steal<object>(api.PyArray_NewFromDescr_(
+            api.PyArray_Type_,
+            descr.release().ptr(),
+            (int) ndim,
+            // Use reinterpret_cast for PyPy on Windows (remove if fixed, checked on 7.3.1)
+            reinterpret_cast<Py_intptr_t *>(shape->data()),
+            reinterpret_cast<Py_intptr_t *>(strides->data()),
+            const_cast<void *>(ptr),
+            flags,
+            nullptr));
+        if (!tmp) {
+            throw error_already_set();
+        }
+        if (ptr) {
+            if (base) {
+                api.PyArray_SetBaseObject_(tmp.ptr(), base.inc_ref().ptr());
+            } else {
+                tmp = reinterpret_steal<object>(
+                    api.PyArray_NewCopy_(tmp.ptr(), -1 /* any order */));
+            }
+        }
+        m_ptr = tmp.release().ptr();
+    }
+
+    array(const pybind11::dtype &dt,
+          ShapeContainer shape,
+          const void *ptr = nullptr,
+          handle base = handle())
+        : array(dt, std::move(shape), {}, ptr, base) {}
+
+    template <typename T,
+              typename
+              = detail::enable_if_t<std::is_integral<T>::value && !std::is_same<bool, T>::value>>
+    array(const pybind11::dtype &dt, T count, const void *ptr = nullptr, handle base = handle())
+        : array(dt, {{count}}, ptr, base) {}
+
+    template <typename T>
+    array(ShapeContainer shape, StridesContainer strides, const T *ptr, handle base = handle())
+        : array(pybind11::dtype::of<T>(), std::move(shape), std::move(strides), ptr, base) {}
+
+    template <typename T>
+    array(ShapeContainer shape, const T *ptr, handle base = handle())
+        : array(std::move(shape), {}, ptr, base) {}
+
+    template <typename T>
+    explicit array(ssize_t count, const T *ptr, handle base = handle())
+        : array({count}, {}, ptr, base) {}
+
+    explicit array(const buffer_info &info, handle base = handle())
+        : array(pybind11::dtype(info), info.shape, info.strides, info.ptr, base) {}
+
+    /// Array descriptor (dtype)
+    pybind11::dtype dtype() const {
+        return reinterpret_borrow<pybind11::dtype>(detail::array_proxy(m_ptr)->descr);
+    }
+
+    /// Total number of elements
+    ssize_t size() const {
+        return std::accumulate(shape(), shape() + ndim(), (ssize_t) 1, std::multiplies<ssize_t>());
+    }
+
+    /// Byte size of a single element
+    ssize_t itemsize() const {
+        return detail::array_descriptor_proxy(detail::array_proxy(m_ptr)->descr)->elsize;
+    }
+
+    /// Total number of bytes
+    ssize_t nbytes() const { return size() * itemsize(); }
+
+    /// Number of dimensions
+    ssize_t ndim() const { return detail::array_proxy(m_ptr)->nd; }
+
+    /// Base object
+    object base() const { return reinterpret_borrow<object>(detail::array_proxy(m_ptr)->base); }
+
+    /// Dimensions of the array
+    const ssize_t *shape() const { return detail::array_proxy(m_ptr)->dimensions; }
+
+    /// Dimension along a given axis
+    ssize_t shape(ssize_t dim) const {
+        if (dim >= ndim()) {
+            fail_dim_check(dim, "invalid axis");
+        }
+        return shape()[dim];
+    }
+
+    /// Strides of the array
+    const ssize_t *strides() const { return detail::array_proxy(m_ptr)->strides; }
+
+    /// Stride along a given axis
+    ssize_t strides(ssize_t dim) const {
+        if (dim >= ndim()) {
+            fail_dim_check(dim, "invalid axis");
+        }
+        return strides()[dim];
+    }
+
+    /// Return the NumPy array flags
+    int flags() const { return detail::array_proxy(m_ptr)->flags; }
+
+    /// If set, the array is writeable (otherwise the buffer is read-only)
+    bool writeable() const {
+        return detail::check_flags(m_ptr, detail::npy_api::NPY_ARRAY_WRITEABLE_);
+    }
+
+    /// If set, the array owns the data (will be freed when the array is deleted)
+    bool owndata() const {
+        return detail::check_flags(m_ptr, detail::npy_api::NPY_ARRAY_OWNDATA_);
+    }
+
+    /// Pointer to the contained data. If index is not provided, points to the
+    /// beginning of the buffer. May throw if the index would lead to out of bounds access.
+    template <typename... Ix>
+    const void *data(Ix... index) const {
+        return static_cast<const void *>(detail::array_proxy(m_ptr)->data + offset_at(index...));
+    }
+
+    /// Mutable pointer to the contained data. If index is not provided, points to the
+    /// beginning of the buffer. May throw if the index would lead to out of bounds access.
+    /// May throw if the array is not writeable.
+    template <typename... Ix>
+    void *mutable_data(Ix... index) {
+        check_writeable();
+        return static_cast<void *>(detail::array_proxy(m_ptr)->data + offset_at(index...));
+    }
+
+    /// Byte offset from beginning of the array to a given index (full or partial).
+    /// May throw if the index would lead to out of bounds access.
+    template <typename... Ix>
+    ssize_t offset_at(Ix... index) const {
+        if ((ssize_t) sizeof...(index) > ndim()) {
+            fail_dim_check(sizeof...(index), "too many indices for an array");
+        }
+        return byte_offset(ssize_t(index)...);
+    }
+
+    ssize_t offset_at() const { return 0; }
+
+    /// Item count from beginning of the array to a given index (full or partial).
+    /// May throw if the index would lead to out of bounds access.
+    template <typename... Ix>
+    ssize_t index_at(Ix... index) const {
+        return offset_at(index...) / itemsize();
+    }
+
+    /**
+     * Returns a proxy object that provides access to the array's data without bounds or
+     * dimensionality checking.  Will throw if the array is missing the `writeable` flag.  Use with
+     * care: the array must not be destroyed or reshaped for the duration of the returned object,
+     * and the caller must take care not to access invalid dimensions or dimension indices.
+     */
+    template <typename T, ssize_t Dims = -1>
+    detail::unchecked_mutable_reference<T, Dims> mutable_unchecked() & {
+        if (PYBIND11_SILENCE_MSVC_C4127(Dims >= 0) && ndim() != Dims) {
+            throw std::domain_error("array has incorrect number of dimensions: "
+                                    + std::to_string(ndim()) + "; expected "
+                                    + std::to_string(Dims));
+        }
+        return detail::unchecked_mutable_reference<T, Dims>(
+            mutable_data(), shape(), strides(), ndim());
+    }
+
+    /**
+     * Returns a proxy object that provides const access to the array's data without bounds or
+     * dimensionality checking.  Unlike `mutable_unchecked()`, this does not require that the
+     * underlying array have the `writable` flag.  Use with care: the array must not be destroyed
+     * or reshaped for the duration of the returned object, and the caller must take care not to
+     * access invalid dimensions or dimension indices.
+     */
+    template <typename T, ssize_t Dims = -1>
+    detail::unchecked_reference<T, Dims> unchecked() const & {
+        if (PYBIND11_SILENCE_MSVC_C4127(Dims >= 0) && ndim() != Dims) {
+            throw std::domain_error("array has incorrect number of dimensions: "
+                                    + std::to_string(ndim()) + "; expected "
+                                    + std::to_string(Dims));
+        }
+        return detail::unchecked_reference<T, Dims>(data(), shape(), strides(), ndim());
+    }
+
+    /// Return a new view with all of the dimensions of length 1 removed
+    array squeeze() {
+        auto &api = detail::npy_api::get();
+        return reinterpret_steal<array>(api.PyArray_Squeeze_(m_ptr));
+    }
+
+    /// Resize array to given shape
+    /// If refcheck is true and more that one reference exist to this array
+    /// then resize will succeed only if it makes a reshape, i.e. original size doesn't change
+    void resize(ShapeContainer new_shape, bool refcheck = true) {
+        detail::npy_api::PyArray_Dims d
+            = {// Use reinterpret_cast for PyPy on Windows (remove if fixed, checked on 7.3.1)
+               reinterpret_cast<Py_intptr_t *>(new_shape->data()),
+               int(new_shape->size())};
+        // try to resize, set ordering param to -1 cause it's not used anyway
+        auto new_array = reinterpret_steal<object>(
+            detail::npy_api::get().PyArray_Resize_(m_ptr, &d, int(refcheck), -1));
+        if (!new_array) {
+            throw error_already_set();
+        }
+        if (isinstance<array>(new_array)) {
+            *this = std::move(new_array);
+        }
+    }
+
+    /// Optional `order` parameter omitted, to be added as needed.
+    array reshape(ShapeContainer new_shape) {
+        detail::npy_api::PyArray_Dims d
+            = {reinterpret_cast<Py_intptr_t *>(new_shape->data()), int(new_shape->size())};
+        auto new_array
+            = reinterpret_steal<array>(detail::npy_api::get().PyArray_Newshape_(m_ptr, &d, 0));
+        if (!new_array) {
+            throw error_already_set();
+        }
+        return new_array;
+    }
+
+    /// Create a view of an array in a different data type.
+    /// This function may fundamentally reinterpret the data in the array.
+    /// It is the responsibility of the caller to ensure that this is safe.
+    /// Only supports the `dtype` argument, the `type` argument is omitted,
+    /// to be added as needed.
+    array view(const std::string &dtype) {
+        auto &api = detail::npy_api::get();
+        auto new_view = reinterpret_steal<array>(api.PyArray_View_(
+            m_ptr, dtype::from_args(pybind11::str(dtype)).release().ptr(), nullptr));
+        if (!new_view) {
+            throw error_already_set();
+        }
+        return new_view;
+    }
+
+    /// Ensure that the argument is a NumPy array
+    /// In case of an error, nullptr is returned and the Python error is cleared.
+    static array ensure(handle h, int ExtraFlags = 0) {
+        auto result = reinterpret_steal<array>(raw_array(h.ptr(), ExtraFlags));
+        if (!result) {
+            PyErr_Clear();
+        }
+        return result;
+    }
+
+protected:
+    template <typename, typename>
+    friend struct detail::npy_format_descriptor;
+
+    void fail_dim_check(ssize_t dim, const std::string &msg) const {
+        throw index_error(msg + ": " + std::to_string(dim) + " (ndim = " + std::to_string(ndim())
+                          + ')');
+    }
+
+    template <typename... Ix>
+    ssize_t byte_offset(Ix... index) const {
+        check_dimensions(index...);
+        return detail::byte_offset_unsafe(strides(), ssize_t(index)...);
+    }
+
+    void check_writeable() const {
+        if (!writeable()) {
+            throw std::domain_error("array is not writeable");
+        }
+    }
+
+    template <typename... Ix>
+    void check_dimensions(Ix... index) const {
+        check_dimensions_impl(ssize_t(0), shape(), ssize_t(index)...);
+    }
+
+    void check_dimensions_impl(ssize_t, const ssize_t *) const {}
+
+    template <typename... Ix>
+    void check_dimensions_impl(ssize_t axis, const ssize_t *shape, ssize_t i, Ix... index) const {
+        if (i >= *shape) {
+            throw index_error(std::string("index ") + std::to_string(i)
+                              + " is out of bounds for axis " + std::to_string(axis)
+                              + " with size " + std::to_string(*shape));
+        }
+        check_dimensions_impl(axis + 1, shape + 1, index...);
+    }
+
+    /// Create array from any object -- always returns a new reference
+    static PyObject *raw_array(PyObject *ptr, int ExtraFlags = 0) {
+        if (ptr == nullptr) {
+            PyErr_SetString(PyExc_ValueError, "cannot create a pybind11::array from a nullptr");
+            return nullptr;
+        }
+        return detail::npy_api::get().PyArray_FromAny_(
+            ptr, nullptr, 0, 0, detail::npy_api::NPY_ARRAY_ENSUREARRAY_ | ExtraFlags, nullptr);
+    }
+};
+
+template <typename T, int ExtraFlags = array::forcecast>
+class array_t : public array {
+private:
+    struct private_ctor {};
+    // Delegating constructor needed when both moving and accessing in the same constructor
+    array_t(private_ctor,
+            ShapeContainer &&shape,
+            StridesContainer &&strides,
+            const T *ptr,
+            handle base)
+        : array(std::move(shape), std::move(strides), ptr, base) {}
+
+public:
+    static_assert(!detail::array_info<T>::is_array, "Array types cannot be used with array_t");
+
+    using value_type = T;
+
+    array_t() : array(0, static_cast<const T *>(nullptr)) {}
+    array_t(handle h, borrowed_t) : array(h, borrowed_t{}) {}
+    array_t(handle h, stolen_t) : array(h, stolen_t{}) {}
+
+    PYBIND11_DEPRECATED("Use array_t<T>::ensure() instead")
+    array_t(handle h, bool is_borrowed) : array(raw_array_t(h.ptr()), stolen_t{}) {
+        if (!m_ptr) {
+            PyErr_Clear();
+        }
+        if (!is_borrowed) {
+            Py_XDECREF(h.ptr());
+        }
+    }
+
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    array_t(const object &o) : array(raw_array_t(o.ptr()), stolen_t{}) {
+        if (!m_ptr) {
+            throw error_already_set();
+        }
+    }
+
+    explicit array_t(const buffer_info &info, handle base = handle()) : array(info, base) {}
+
+    array_t(ShapeContainer shape,
+            StridesContainer strides,
+            const T *ptr = nullptr,
+            handle base = handle())
+        : array(std::move(shape), std::move(strides), ptr, base) {}
+
+    explicit array_t(ShapeContainer shape, const T *ptr = nullptr, handle base = handle())
+        : array_t(private_ctor{},
+                  std::move(shape),
+                  (ExtraFlags & f_style) != 0 ? detail::f_strides(*shape, itemsize())
+                                              : detail::c_strides(*shape, itemsize()),
+                  ptr,
+                  base) {}
+
+    explicit array_t(ssize_t count, const T *ptr = nullptr, handle base = handle())
+        : array({count}, {}, ptr, base) {}
+
+    constexpr ssize_t itemsize() const { return sizeof(T); }
+
+    template <typename... Ix>
+    ssize_t index_at(Ix... index) const {
+        return offset_at(index...) / itemsize();
+    }
+
+    template <typename... Ix>
+    const T *data(Ix... index) const {
+        return static_cast<const T *>(array::data(index...));
+    }
+
+    template <typename... Ix>
+    T *mutable_data(Ix... index) {
+        return static_cast<T *>(array::mutable_data(index...));
+    }
+
+    // Reference to element at a given index
+    template <typename... Ix>
+    const T &at(Ix... index) const {
+        if ((ssize_t) sizeof...(index) != ndim()) {
+            fail_dim_check(sizeof...(index), "index dimension mismatch");
+        }
+        return *(static_cast<const T *>(array::data())
+                 + byte_offset(ssize_t(index)...) / itemsize());
+    }
+
+    // Mutable reference to element at a given index
+    template <typename... Ix>
+    T &mutable_at(Ix... index) {
+        if ((ssize_t) sizeof...(index) != ndim()) {
+            fail_dim_check(sizeof...(index), "index dimension mismatch");
+        }
+        return *(static_cast<T *>(array::mutable_data())
+                 + byte_offset(ssize_t(index)...) / itemsize());
+    }
+
+    /**
+     * Returns a proxy object that provides access to the array's data without bounds or
+     * dimensionality checking.  Will throw if the array is missing the `writeable` flag.  Use with
+     * care: the array must not be destroyed or reshaped for the duration of the returned object,
+     * and the caller must take care not to access invalid dimensions or dimension indices.
+     */
+    template <ssize_t Dims = -1>
+    detail::unchecked_mutable_reference<T, Dims> mutable_unchecked() & {
+        return array::mutable_unchecked<T, Dims>();
+    }
+
+    /**
+     * Returns a proxy object that provides const access to the array's data without bounds or
+     * dimensionality checking.  Unlike `unchecked()`, this does not require that the underlying
+     * array have the `writable` flag.  Use with care: the array must not be destroyed or reshaped
+     * for the duration of the returned object, and the caller must take care not to access invalid
+     * dimensions or dimension indices.
+     */
+    template <ssize_t Dims = -1>
+    detail::unchecked_reference<T, Dims> unchecked() const & {
+        return array::unchecked<T, Dims>();
+    }
+
+    /// Ensure that the argument is a NumPy array of the correct dtype (and if not, try to convert
+    /// it).  In case of an error, nullptr is returned and the Python error is cleared.
+    static array_t ensure(handle h) {
+        auto result = reinterpret_steal<array_t>(raw_array_t(h.ptr()));
+        if (!result) {
+            PyErr_Clear();
+        }
+        return result;
+    }
+
+    static bool check_(handle h) {
+        const auto &api = detail::npy_api::get();
+        return api.PyArray_Check_(h.ptr())
+               && api.PyArray_EquivTypes_(detail::array_proxy(h.ptr())->descr,
+                                          dtype::of<T>().ptr())
+               && detail::check_flags(h.ptr(), ExtraFlags & (array::c_style | array::f_style));
+    }
+
+protected:
+    /// Create array from any object -- always returns a new reference
+    static PyObject *raw_array_t(PyObject *ptr) {
+        if (ptr == nullptr) {
+            PyErr_SetString(PyExc_ValueError, "cannot create a pybind11::array_t from a nullptr");
+            return nullptr;
+        }
+        return detail::npy_api::get().PyArray_FromAny_(ptr,
+                                                       dtype::of<T>().release().ptr(),
+                                                       0,
+                                                       0,
+                                                       detail::npy_api::NPY_ARRAY_ENSUREARRAY_
+                                                           | ExtraFlags,
+                                                       nullptr);
+    }
+};
+
+template <typename T>
+struct format_descriptor<T, detail::enable_if_t<detail::is_pod_struct<T>::value>> {
+    static std::string format() {
+        return detail::npy_format_descriptor<typename std::remove_cv<T>::type>::format();
+    }
+};
+
+template <size_t N>
+struct format_descriptor<char[N]> {
+    static std::string format() { return std::to_string(N) + 's'; }
+};
+template <size_t N>
+struct format_descriptor<std::array<char, N>> {
+    static std::string format() { return std::to_string(N) + 's'; }
+};
+
+template <typename T>
+struct format_descriptor<T, detail::enable_if_t<std::is_enum<T>::value>> {
+    static std::string format() {
+        return format_descriptor<
+            typename std::remove_cv<typename std::underlying_type<T>::type>::type>::format();
+    }
+};
+
+template <typename T>
+struct format_descriptor<T, detail::enable_if_t<detail::array_info<T>::is_array>> {
+    static std::string format() {
+        using namespace detail;
+        static constexpr auto extents = const_name("(") + array_info<T>::extents + const_name(")");
+        return extents.text + format_descriptor<remove_all_extents_t<T>>::format();
+    }
+};
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+template <typename T, int ExtraFlags>
+struct pyobject_caster<array_t<T, ExtraFlags>> {
+    using type = array_t<T, ExtraFlags>;
+
+    bool load(handle src, bool convert) {
+        if (!convert && !type::check_(src)) {
+            return false;
+        }
+        value = type::ensure(src);
+        return static_cast<bool>(value);
+    }
+
+    static handle cast(const handle &src, return_value_policy /* policy */, handle /* parent */) {
+        return src.inc_ref();
+    }
+    PYBIND11_TYPE_CASTER(type, handle_type_name<type>::name);
+};
+
+template <typename T>
+struct compare_buffer_info<T, detail::enable_if_t<detail::is_pod_struct<T>::value>> {
+    static bool compare(const buffer_info &b) {
+        return npy_api::get().PyArray_EquivTypes_(dtype::of<T>().ptr(), dtype(b).ptr());
+    }
+};
+
+template <typename T, typename = void>
+struct npy_format_descriptor_name;
+
+template <typename T>
+struct npy_format_descriptor_name<T, enable_if_t<std::is_integral<T>::value>> {
+    static constexpr auto name = const_name<std::is_same<T, bool>::value>(
+        const_name("bool"),
+        const_name<std::is_signed<T>::value>("numpy.int", "numpy.uint")
+            + const_name<sizeof(T) * 8>());
+};
+
+template <typename T>
+struct npy_format_descriptor_name<T, enable_if_t<std::is_floating_point<T>::value>> {
+    static constexpr auto name = const_name < std::is_same<T, float>::value
+                                 || std::is_same<T, const float>::value
+                                 || std::is_same<T, double>::value
+                                 || std::is_same<T, const double>::value
+                                        > (const_name("numpy.float") + const_name<sizeof(T) * 8>(),
+                                           const_name("numpy.longdouble"));
+};
+
+template <typename T>
+struct npy_format_descriptor_name<T, enable_if_t<is_complex<T>::value>> {
+    static constexpr auto name = const_name < std::is_same<typename T::value_type, float>::value
+                                 || std::is_same<typename T::value_type, const float>::value
+                                 || std::is_same<typename T::value_type, double>::value
+                                 || std::is_same<typename T::value_type, const double>::value
+                                        > (const_name("numpy.complex")
+                                               + const_name<sizeof(typename T::value_type) * 16>(),
+                                           const_name("numpy.longcomplex"));
+};
+
+template <typename T>
+struct npy_format_descriptor<
+    T,
+    enable_if_t<satisfies_any_of<T, std::is_arithmetic, is_complex>::value>>
+    : npy_format_descriptor_name<T> {
+private:
+    // NB: the order here must match the one in common.h
+    constexpr static const int values[15] = {npy_api::NPY_BOOL_,
+                                             npy_api::NPY_BYTE_,
+                                             npy_api::NPY_UBYTE_,
+                                             npy_api::NPY_INT16_,
+                                             npy_api::NPY_UINT16_,
+                                             npy_api::NPY_INT32_,
+                                             npy_api::NPY_UINT32_,
+                                             npy_api::NPY_INT64_,
+                                             npy_api::NPY_UINT64_,
+                                             npy_api::NPY_FLOAT_,
+                                             npy_api::NPY_DOUBLE_,
+                                             npy_api::NPY_LONGDOUBLE_,
+                                             npy_api::NPY_CFLOAT_,
+                                             npy_api::NPY_CDOUBLE_,
+                                             npy_api::NPY_CLONGDOUBLE_};
+
+public:
+    static constexpr int value = values[detail::is_fmt_numeric<T>::index];
+
+    static pybind11::dtype dtype() {
+        if (auto *ptr = npy_api::get().PyArray_DescrFromType_(value)) {
+            return reinterpret_steal<pybind11::dtype>(ptr);
+        }
+        pybind11_fail("Unsupported buffer format!");
+    }
+};
+
+#define PYBIND11_DECL_CHAR_FMT                                                                    \
+    static constexpr auto name = const_name("S") + const_name<N>();                               \
+    static pybind11::dtype dtype() {                                                              \
+        return pybind11::dtype(std::string("S") + std::to_string(N));                             \
+    }
+template <size_t N>
+struct npy_format_descriptor<char[N]> {
+    PYBIND11_DECL_CHAR_FMT
+};
+template <size_t N>
+struct npy_format_descriptor<std::array<char, N>> {
+    PYBIND11_DECL_CHAR_FMT
+};
+#undef PYBIND11_DECL_CHAR_FMT
+
+template <typename T>
+struct npy_format_descriptor<T, enable_if_t<array_info<T>::is_array>> {
+private:
+    using base_descr = npy_format_descriptor<typename array_info<T>::type>;
+
+public:
+    static_assert(!array_info<T>::is_empty, "Zero-sized arrays are not supported");
+
+    static constexpr auto name
+        = const_name("(") + array_info<T>::extents + const_name(")") + base_descr::name;
+    static pybind11::dtype dtype() {
+        list shape;
+        array_info<T>::append_extents(shape);
+        return pybind11::dtype::from_args(
+            pybind11::make_tuple(base_descr::dtype(), std::move(shape)));
+    }
+};
+
+template <typename T>
+struct npy_format_descriptor<T, enable_if_t<std::is_enum<T>::value>> {
+private:
+    using base_descr = npy_format_descriptor<typename std::underlying_type<T>::type>;
+
+public:
+    static constexpr auto name = base_descr::name;
+    static pybind11::dtype dtype() { return base_descr::dtype(); }
+};
+
+struct field_descriptor {
+    const char *name;
+    ssize_t offset;
+    ssize_t size;
+    std::string format;
+    dtype descr;
+};
+
+PYBIND11_NOINLINE void register_structured_dtype(any_container<field_descriptor> fields,
+                                                 const std::type_info &tinfo,
+                                                 ssize_t itemsize,
+                                                 bool (*direct_converter)(PyObject *, void *&)) {
+
+    auto &numpy_internals = get_numpy_internals();
+    if (numpy_internals.get_type_info(tinfo, false)) {
+        pybind11_fail("NumPy: dtype is already registered");
+    }
+
+    // Use ordered fields because order matters as of NumPy 1.14:
+    // https://docs.scipy.org/doc/numpy/release.html#multiple-field-indexing-assignment-of-structured-arrays
+    std::vector<field_descriptor> ordered_fields(std::move(fields));
+    std::sort(
+        ordered_fields.begin(),
+        ordered_fields.end(),
+        [](const field_descriptor &a, const field_descriptor &b) { return a.offset < b.offset; });
+
+    list names, formats, offsets;
+    for (auto &field : ordered_fields) {
+        if (!field.descr) {
+            pybind11_fail(std::string("NumPy: unsupported field dtype: `") + field.name + "` @ "
+                          + tinfo.name());
+        }
+        names.append(pybind11::str(field.name));
+        formats.append(field.descr);
+        offsets.append(pybind11::int_(field.offset));
+    }
+    auto *dtype_ptr
+        = pybind11::dtype(std::move(names), std::move(formats), std::move(offsets), itemsize)
+              .release()
+              .ptr();
+
+    // There is an existing bug in NumPy (as of v1.11): trailing bytes are
+    // not encoded explicitly into the format string. This will supposedly
+    // get fixed in v1.12; for further details, see these:
+    // - https://github.com/numpy/numpy/issues/7797
+    // - https://github.com/numpy/numpy/pull/7798
+    // Because of this, we won't use numpy's logic to generate buffer format
+    // strings and will just do it ourselves.
+    ssize_t offset = 0;
+    std::ostringstream oss;
+    // mark the structure as unaligned with '^', because numpy and C++ don't
+    // always agree about alignment (particularly for complex), and we're
+    // explicitly listing all our padding. This depends on none of the fields
+    // overriding the endianness. Putting the ^ in front of individual fields
+    // isn't guaranteed to work due to https://github.com/numpy/numpy/issues/9049
+    oss << "^T{";
+    for (auto &field : ordered_fields) {
+        if (field.offset > offset) {
+            oss << (field.offset - offset) << 'x';
+        }
+        oss << field.format << ':' << field.name << ':';
+        offset = field.offset + field.size;
+    }
+    if (itemsize > offset) {
+        oss << (itemsize - offset) << 'x';
+    }
+    oss << '}';
+    auto format_str = oss.str();
+
+    // Sanity check: verify that NumPy properly parses our buffer format string
+    auto &api = npy_api::get();
+    auto arr = array(buffer_info(nullptr, itemsize, format_str, 1));
+    if (!api.PyArray_EquivTypes_(dtype_ptr, arr.dtype().ptr())) {
+        pybind11_fail("NumPy: invalid buffer descriptor!");
+    }
+
+    auto tindex = std::type_index(tinfo);
+    numpy_internals.registered_dtypes[tindex] = {dtype_ptr, std::move(format_str)};
+    get_internals().direct_conversions[tindex].push_back(direct_converter);
+}
+
+template <typename T, typename SFINAE>
+struct npy_format_descriptor {
+    static_assert(is_pod_struct<T>::value,
+                  "Attempt to use a non-POD or unimplemented POD type as a numpy dtype");
+
+    static constexpr auto name = make_caster<T>::name;
+
+    static pybind11::dtype dtype() { return reinterpret_borrow<pybind11::dtype>(dtype_ptr()); }
+
+    static std::string format() {
+        static auto format_str = get_numpy_internals().get_type_info<T>(true)->format_str;
+        return format_str;
+    }
+
+    static void register_dtype(any_container<field_descriptor> fields) {
+        register_structured_dtype(std::move(fields),
+                                  typeid(typename std::remove_cv<T>::type),
+                                  sizeof(T),
+                                  &direct_converter);
+    }
+
+private:
+    static PyObject *dtype_ptr() {
+        static PyObject *ptr = get_numpy_internals().get_type_info<T>(true)->dtype_ptr;
+        return ptr;
+    }
+
+    static bool direct_converter(PyObject *obj, void *&value) {
+        auto &api = npy_api::get();
+        if (!PyObject_TypeCheck(obj, api.PyVoidArrType_Type_)) {
+            return false;
+        }
+        if (auto descr = reinterpret_steal<object>(api.PyArray_DescrFromScalar_(obj))) {
+            if (api.PyArray_EquivTypes_(dtype_ptr(), descr.ptr())) {
+                value = ((PyVoidScalarObject_Proxy *) obj)->obval;
+                return true;
+            }
+        }
+        return false;
+    }
+};
+
+#ifdef __CLION_IDE__ // replace heavy macro with dummy code for the IDE (doesn't affect code)
+#    define PYBIND11_NUMPY_DTYPE(Type, ...) ((void) 0)
+#    define PYBIND11_NUMPY_DTYPE_EX(Type, ...) ((void) 0)
+#else
+
+#    define PYBIND11_FIELD_DESCRIPTOR_EX(T, Field, Name)                                          \
+        ::pybind11::detail::field_descriptor {                                                    \
+            Name, offsetof(T, Field), sizeof(decltype(std::declval<T>().Field)),                  \
+                ::pybind11::format_descriptor<decltype(std::declval<T>().Field)>::format(),       \
+                ::pybind11::detail::npy_format_descriptor<                                        \
+                    decltype(std::declval<T>().Field)>::dtype()                                   \
+        }
+
+// Extract name, offset and format descriptor for a struct field
+#    define PYBIND11_FIELD_DESCRIPTOR(T, Field) PYBIND11_FIELD_DESCRIPTOR_EX(T, Field, #    Field)
+
+// The main idea of this macro is borrowed from https://github.com/swansontec/map-macro
+// (C) William Swanson, Paul Fultz
+#    define PYBIND11_EVAL0(...) __VA_ARGS__
+#    define PYBIND11_EVAL1(...) PYBIND11_EVAL0(PYBIND11_EVAL0(PYBIND11_EVAL0(__VA_ARGS__)))
+#    define PYBIND11_EVAL2(...) PYBIND11_EVAL1(PYBIND11_EVAL1(PYBIND11_EVAL1(__VA_ARGS__)))
+#    define PYBIND11_EVAL3(...) PYBIND11_EVAL2(PYBIND11_EVAL2(PYBIND11_EVAL2(__VA_ARGS__)))
+#    define PYBIND11_EVAL4(...) PYBIND11_EVAL3(PYBIND11_EVAL3(PYBIND11_EVAL3(__VA_ARGS__)))
+#    define PYBIND11_EVAL(...) PYBIND11_EVAL4(PYBIND11_EVAL4(PYBIND11_EVAL4(__VA_ARGS__)))
+#    define PYBIND11_MAP_END(...)
+#    define PYBIND11_MAP_OUT
+#    define PYBIND11_MAP_COMMA ,
+#    define PYBIND11_MAP_GET_END() 0, PYBIND11_MAP_END
+#    define PYBIND11_MAP_NEXT0(test, next, ...) next PYBIND11_MAP_OUT
+#    define PYBIND11_MAP_NEXT1(test, next) PYBIND11_MAP_NEXT0(test, next, 0)
+#    define PYBIND11_MAP_NEXT(test, next) PYBIND11_MAP_NEXT1(PYBIND11_MAP_GET_END test, next)
+#    if defined(_MSC_VER)                                                                         \
+        && !defined(__clang__) // MSVC is not as eager to expand macros, hence this workaround
+#        define PYBIND11_MAP_LIST_NEXT1(test, next)                                               \
+            PYBIND11_EVAL0(PYBIND11_MAP_NEXT0(test, PYBIND11_MAP_COMMA next, 0))
+#    else
+#        define PYBIND11_MAP_LIST_NEXT1(test, next)                                               \
+            PYBIND11_MAP_NEXT0(test, PYBIND11_MAP_COMMA next, 0)
+#    endif
+#    define PYBIND11_MAP_LIST_NEXT(test, next)                                                    \
+        PYBIND11_MAP_LIST_NEXT1(PYBIND11_MAP_GET_END test, next)
+#    define PYBIND11_MAP_LIST0(f, t, x, peek, ...)                                                \
+        f(t, x) PYBIND11_MAP_LIST_NEXT(peek, PYBIND11_MAP_LIST1)(f, t, peek, __VA_ARGS__)
+#    define PYBIND11_MAP_LIST1(f, t, x, peek, ...)                                                \
+        f(t, x) PYBIND11_MAP_LIST_NEXT(peek, PYBIND11_MAP_LIST0)(f, t, peek, __VA_ARGS__)
+// PYBIND11_MAP_LIST(f, t, a1, a2, ...) expands to f(t, a1), f(t, a2), ...
+#    define PYBIND11_MAP_LIST(f, t, ...)                                                          \
+        PYBIND11_EVAL(PYBIND11_MAP_LIST1(f, t, __VA_ARGS__, (), 0))
+
+#    define PYBIND11_NUMPY_DTYPE(Type, ...)                                                       \
+        ::pybind11::detail::npy_format_descriptor<Type>::register_dtype(                          \
+            ::std::vector<::pybind11::detail::field_descriptor>{                                  \
+                PYBIND11_MAP_LIST(PYBIND11_FIELD_DESCRIPTOR, Type, __VA_ARGS__)})
+
+#    if defined(_MSC_VER) && !defined(__clang__)
+#        define PYBIND11_MAP2_LIST_NEXT1(test, next)                                              \
+            PYBIND11_EVAL0(PYBIND11_MAP_NEXT0(test, PYBIND11_MAP_COMMA next, 0))
+#    else
+#        define PYBIND11_MAP2_LIST_NEXT1(test, next)                                              \
+            PYBIND11_MAP_NEXT0(test, PYBIND11_MAP_COMMA next, 0)
+#    endif
+#    define PYBIND11_MAP2_LIST_NEXT(test, next)                                                   \
+        PYBIND11_MAP2_LIST_NEXT1(PYBIND11_MAP_GET_END test, next)
+#    define PYBIND11_MAP2_LIST0(f, t, x1, x2, peek, ...)                                          \
+        f(t, x1, x2) PYBIND11_MAP2_LIST_NEXT(peek, PYBIND11_MAP2_LIST1)(f, t, peek, __VA_ARGS__)
+#    define PYBIND11_MAP2_LIST1(f, t, x1, x2, peek, ...)                                          \
+        f(t, x1, x2) PYBIND11_MAP2_LIST_NEXT(peek, PYBIND11_MAP2_LIST0)(f, t, peek, __VA_ARGS__)
+// PYBIND11_MAP2_LIST(f, t, a1, a2, ...) expands to f(t, a1, a2), f(t, a3, a4), ...
+#    define PYBIND11_MAP2_LIST(f, t, ...)                                                         \
+        PYBIND11_EVAL(PYBIND11_MAP2_LIST1(f, t, __VA_ARGS__, (), 0))
+
+#    define PYBIND11_NUMPY_DTYPE_EX(Type, ...)                                                    \
+        ::pybind11::detail::npy_format_descriptor<Type>::register_dtype(                          \
+            ::std::vector<::pybind11::detail::field_descriptor>{                                  \
+                PYBIND11_MAP2_LIST(PYBIND11_FIELD_DESCRIPTOR_EX, Type, __VA_ARGS__)})
+
+#endif // __CLION_IDE__
+
+class common_iterator {
+public:
+    using container_type = std::vector<ssize_t>;
+    using value_type = container_type::value_type;
+    using size_type = container_type::size_type;
+
+    common_iterator() : m_strides() {}
+
+    common_iterator(void *ptr, const container_type &strides, const container_type &shape)
+        : p_ptr(reinterpret_cast<char *>(ptr)), m_strides(strides.size()) {
+        m_strides.back() = static_cast<value_type>(strides.back());
+        for (size_type i = m_strides.size() - 1; i != 0; --i) {
+            size_type j = i - 1;
+            auto s = static_cast<value_type>(shape[i]);
+            m_strides[j] = strides[j] + m_strides[i] - strides[i] * s;
+        }
+    }
+
+    void increment(size_type dim) { p_ptr += m_strides[dim]; }
+
+    void *data() const { return p_ptr; }
+
+private:
+    char *p_ptr{nullptr};
+    container_type m_strides;
+};
+
+template <size_t N>
+class multi_array_iterator {
+public:
+    using container_type = std::vector<ssize_t>;
+
+    multi_array_iterator(const std::array<buffer_info, N> &buffers, const container_type &shape)
+        : m_shape(shape.size()), m_index(shape.size(), 0), m_common_iterator() {
+
+        // Manual copy to avoid conversion warning if using std::copy
+        for (size_t i = 0; i < shape.size(); ++i) {
+            m_shape[i] = shape[i];
+        }
+
+        container_type strides(shape.size());
+        for (size_t i = 0; i < N; ++i) {
+            init_common_iterator(buffers[i], shape, m_common_iterator[i], strides);
+        }
+    }
+
+    multi_array_iterator &operator++() {
+        for (size_t j = m_index.size(); j != 0; --j) {
+            size_t i = j - 1;
+            if (++m_index[i] != m_shape[i]) {
+                increment_common_iterator(i);
+                break;
+            }
+            m_index[i] = 0;
+        }
+        return *this;
+    }
+
+    template <size_t K, class T = void>
+    T *data() const {
+        return reinterpret_cast<T *>(m_common_iterator[K].data());
+    }
+
+private:
+    using common_iter = common_iterator;
+
+    void init_common_iterator(const buffer_info &buffer,
+                              const container_type &shape,
+                              common_iter &iterator,
+                              container_type &strides) {
+        auto buffer_shape_iter = buffer.shape.rbegin();
+        auto buffer_strides_iter = buffer.strides.rbegin();
+        auto shape_iter = shape.rbegin();
+        auto strides_iter = strides.rbegin();
+
+        while (buffer_shape_iter != buffer.shape.rend()) {
+            if (*shape_iter == *buffer_shape_iter) {
+                *strides_iter = *buffer_strides_iter;
+            } else {
+                *strides_iter = 0;
+            }
+
+            ++buffer_shape_iter;
+            ++buffer_strides_iter;
+            ++shape_iter;
+            ++strides_iter;
+        }
+
+        std::fill(strides_iter, strides.rend(), 0);
+        iterator = common_iter(buffer.ptr, strides, shape);
+    }
+
+    void increment_common_iterator(size_t dim) {
+        for (auto &iter : m_common_iterator) {
+            iter.increment(dim);
+        }
+    }
+
+    container_type m_shape;
+    container_type m_index;
+    std::array<common_iter, N> m_common_iterator;
+};
+
+enum class broadcast_trivial { non_trivial, c_trivial, f_trivial };
+
+// Populates the shape and number of dimensions for the set of buffers.  Returns a
+// broadcast_trivial enum value indicating whether the broadcast is "trivial"--that is, has each
+// buffer being either a singleton or a full-size, C-contiguous (`c_trivial`) or Fortran-contiguous
+// (`f_trivial`) storage buffer; returns `non_trivial` otherwise.
+template <size_t N>
+broadcast_trivial
+broadcast(const std::array<buffer_info, N> &buffers, ssize_t &ndim, std::vector<ssize_t> &shape) {
+    ndim = std::accumulate(
+        buffers.begin(), buffers.end(), ssize_t(0), [](ssize_t res, const buffer_info &buf) {
+            return std::max(res, buf.ndim);
+        });
+
+    shape.clear();
+    shape.resize((size_t) ndim, 1);
+
+    // Figure out the output size, and make sure all input arrays conform (i.e. are either size 1
+    // or the full size).
+    for (size_t i = 0; i < N; ++i) {
+        auto res_iter = shape.rbegin();
+        auto end = buffers[i].shape.rend();
+        for (auto shape_iter = buffers[i].shape.rbegin(); shape_iter != end;
+             ++shape_iter, ++res_iter) {
+            const auto &dim_size_in = *shape_iter;
+            auto &dim_size_out = *res_iter;
+
+            // Each input dimension can either be 1 or `n`, but `n` values must match across
+            // buffers
+            if (dim_size_out == 1) {
+                dim_size_out = dim_size_in;
+            } else if (dim_size_in != 1 && dim_size_in != dim_size_out) {
+                pybind11_fail("pybind11::vectorize: incompatible size/dimension of inputs!");
+            }
+        }
+    }
+
+    bool trivial_broadcast_c = true;
+    bool trivial_broadcast_f = true;
+    for (size_t i = 0; i < N && (trivial_broadcast_c || trivial_broadcast_f); ++i) {
+        if (buffers[i].size == 1) {
+            continue;
+        }
+
+        // Require the same number of dimensions:
+        if (buffers[i].ndim != ndim) {
+            return broadcast_trivial::non_trivial;
+        }
+
+        // Require all dimensions be full-size:
+        if (!std::equal(buffers[i].shape.cbegin(), buffers[i].shape.cend(), shape.cbegin())) {
+            return broadcast_trivial::non_trivial;
+        }
+
+        // Check for C contiguity (but only if previous inputs were also C contiguous)
+        if (trivial_broadcast_c) {
+            ssize_t expect_stride = buffers[i].itemsize;
+            auto end = buffers[i].shape.crend();
+            for (auto shape_iter = buffers[i].shape.crbegin(),
+                      stride_iter = buffers[i].strides.crbegin();
+                 trivial_broadcast_c && shape_iter != end;
+                 ++shape_iter, ++stride_iter) {
+                if (expect_stride == *stride_iter) {
+                    expect_stride *= *shape_iter;
+                } else {
+                    trivial_broadcast_c = false;
+                }
+            }
+        }
+
+        // Check for Fortran contiguity (if previous inputs were also F contiguous)
+        if (trivial_broadcast_f) {
+            ssize_t expect_stride = buffers[i].itemsize;
+            auto end = buffers[i].shape.cend();
+            for (auto shape_iter = buffers[i].shape.cbegin(),
+                      stride_iter = buffers[i].strides.cbegin();
+                 trivial_broadcast_f && shape_iter != end;
+                 ++shape_iter, ++stride_iter) {
+                if (expect_stride == *stride_iter) {
+                    expect_stride *= *shape_iter;
+                } else {
+                    trivial_broadcast_f = false;
+                }
+            }
+        }
+    }
+
+    return trivial_broadcast_c   ? broadcast_trivial::c_trivial
+           : trivial_broadcast_f ? broadcast_trivial::f_trivial
+                                 : broadcast_trivial::non_trivial;
+}
+
+template <typename T>
+struct vectorize_arg {
+    static_assert(!std::is_rvalue_reference<T>::value,
+                  "Functions with rvalue reference arguments cannot be vectorized");
+    // The wrapped function gets called with this type:
+    using call_type = remove_reference_t<T>;
+    // Is this a vectorized argument?
+    static constexpr bool vectorize
+        = satisfies_any_of<call_type, std::is_arithmetic, is_complex, is_pod>::value
+          && satisfies_none_of<call_type,
+                               std::is_pointer,
+                               std::is_array,
+                               is_std_array,
+                               std::is_enum>::value
+          && (!std::is_reference<T>::value
+              || (std::is_lvalue_reference<T>::value && std::is_const<call_type>::value));
+    // Accept this type: an array for vectorized types, otherwise the type as-is:
+    using type = conditional_t<vectorize, array_t<remove_cv_t<call_type>, array::forcecast>, T>;
+};
+
+// py::vectorize when a return type is present
+template <typename Func, typename Return, typename... Args>
+struct vectorize_returned_array {
+    using Type = array_t<Return>;
+
+    static Type create(broadcast_trivial trivial, const std::vector<ssize_t> &shape) {
+        if (trivial == broadcast_trivial::f_trivial) {
+            return array_t<Return, array::f_style>(shape);
+        }
+        return array_t<Return>(shape);
+    }
+
+    static Return *mutable_data(Type &array) { return array.mutable_data(); }
+
+    static Return call(Func &f, Args &...args) { return f(args...); }
+
+    static void call(Return *out, size_t i, Func &f, Args &...args) { out[i] = f(args...); }
+};
+
+// py::vectorize when a return type is not present
+template <typename Func, typename... Args>
+struct vectorize_returned_array<Func, void, Args...> {
+    using Type = none;
+
+    static Type create(broadcast_trivial, const std::vector<ssize_t> &) { return none(); }
+
+    static void *mutable_data(Type &) { return nullptr; }
+
+    static detail::void_type call(Func &f, Args &...args) {
+        f(args...);
+        return {};
+    }
+
+    static void call(void *, size_t, Func &f, Args &...args) { f(args...); }
+};
+
+template <typename Func, typename Return, typename... Args>
+struct vectorize_helper {
+
+// NVCC for some reason breaks if NVectorized is private
+#ifdef __CUDACC__
+public:
+#else
+private:
+#endif
+
+    static constexpr size_t N = sizeof...(Args);
+    static constexpr size_t NVectorized = constexpr_sum(vectorize_arg<Args>::vectorize...);
+    static_assert(
+        NVectorized >= 1,
+        "pybind11::vectorize(...) requires a function with at least one vectorizable argument");
+
+public:
+    template <typename T,
+              // SFINAE to prevent shadowing the copy constructor.
+              typename = detail::enable_if_t<
+                  !std::is_same<vectorize_helper, typename std::decay<T>::type>::value>>
+    explicit vectorize_helper(T &&f) : f(std::forward<T>(f)) {}
+
+    object operator()(typename vectorize_arg<Args>::type... args) {
+        return run(args...,
+                   make_index_sequence<N>(),
+                   select_indices<vectorize_arg<Args>::vectorize...>(),
+                   make_index_sequence<NVectorized>());
+    }
+
+private:
+    remove_reference_t<Func> f;
+
+    // Internal compiler error in MSVC 19.16.27025.1 (Visual Studio 2017 15.9.4), when compiling
+    // with "/permissive-" flag when arg_call_types is manually inlined.
+    using arg_call_types = std::tuple<typename vectorize_arg<Args>::call_type...>;
+    template <size_t Index>
+    using param_n_t = typename std::tuple_element<Index, arg_call_types>::type;
+
+    using returned_array = vectorize_returned_array<Func, Return, Args...>;
+
+    // Runs a vectorized function given arguments tuple and three index sequences:
+    //     - Index is the full set of 0 ... (N-1) argument indices;
+    //     - VIndex is the subset of argument indices with vectorized parameters, letting us access
+    //       vectorized arguments (anything not in this sequence is passed through)
+    //     - BIndex is a incremental sequence (beginning at 0) of the same size as VIndex, so that
+    //       we can store vectorized buffer_infos in an array (argument VIndex has its buffer at
+    //       index BIndex in the array).
+    template <size_t... Index, size_t... VIndex, size_t... BIndex>
+    object run(typename vectorize_arg<Args>::type &...args,
+               index_sequence<Index...> i_seq,
+               index_sequence<VIndex...> vi_seq,
+               index_sequence<BIndex...> bi_seq) {
+
+        // Pointers to values the function was called with; the vectorized ones set here will start
+        // out as array_t<T> pointers, but they will be changed them to T pointers before we make
+        // call the wrapped function.  Non-vectorized pointers are left as-is.
+        std::array<void *, N> params{{&args...}};
+
+        // The array of `buffer_info`s of vectorized arguments:
+        std::array<buffer_info, NVectorized> buffers{
+            {reinterpret_cast<array *>(params[VIndex])->request()...}};
+
+        /* Determine dimensions parameters of output array */
+        ssize_t nd = 0;
+        std::vector<ssize_t> shape(0);
+        auto trivial = broadcast(buffers, nd, shape);
+        auto ndim = (size_t) nd;
+
+        size_t size
+            = std::accumulate(shape.begin(), shape.end(), (size_t) 1, std::multiplies<size_t>());
+
+        // If all arguments are 0-dimension arrays (i.e. single values) return a plain value (i.e.
+        // not wrapped in an array).
+        if (size == 1 && ndim == 0) {
+            PYBIND11_EXPAND_SIDE_EFFECTS(params[VIndex] = buffers[BIndex].ptr);
+            return cast(
+                returned_array::call(f, *reinterpret_cast<param_n_t<Index> *>(params[Index])...));
+        }
+
+        auto result = returned_array::create(trivial, shape);
+
+        if (size == 0) {
+            return std::move(result);
+        }
+
+        /* Call the function */
+        auto *mutable_data = returned_array::mutable_data(result);
+        if (trivial == broadcast_trivial::non_trivial) {
+            apply_broadcast(buffers, params, mutable_data, size, shape, i_seq, vi_seq, bi_seq);
+        } else {
+            apply_trivial(buffers, params, mutable_data, size, i_seq, vi_seq, bi_seq);
+        }
+
+        return std::move(result);
+    }
+
+    template <size_t... Index, size_t... VIndex, size_t... BIndex>
+    void apply_trivial(std::array<buffer_info, NVectorized> &buffers,
+                       std::array<void *, N> &params,
+                       Return *out,
+                       size_t size,
+                       index_sequence<Index...>,
+                       index_sequence<VIndex...>,
+                       index_sequence<BIndex...>) {
+
+        // Initialize an array of mutable byte references and sizes with references set to the
+        // appropriate pointer in `params`; as we iterate, we'll increment each pointer by its size
+        // (except for singletons, which get an increment of 0).
+        std::array<std::pair<unsigned char *&, const size_t>, NVectorized> vecparams{
+            {std::pair<unsigned char *&, const size_t>(
+                reinterpret_cast<unsigned char *&>(params[VIndex] = buffers[BIndex].ptr),
+                buffers[BIndex].size == 1 ? 0 : sizeof(param_n_t<VIndex>))...}};
+
+        for (size_t i = 0; i < size; ++i) {
+            returned_array::call(
+                out, i, f, *reinterpret_cast<param_n_t<Index> *>(params[Index])...);
+            for (auto &x : vecparams) {
+                x.first += x.second;
+            }
+        }
+    }
+
+    template <size_t... Index, size_t... VIndex, size_t... BIndex>
+    void apply_broadcast(std::array<buffer_info, NVectorized> &buffers,
+                         std::array<void *, N> &params,
+                         Return *out,
+                         size_t size,
+                         const std::vector<ssize_t> &output_shape,
+                         index_sequence<Index...>,
+                         index_sequence<VIndex...>,
+                         index_sequence<BIndex...>) {
+
+        multi_array_iterator<NVectorized> input_iter(buffers, output_shape);
+
+        for (size_t i = 0; i < size; ++i, ++input_iter) {
+            PYBIND11_EXPAND_SIDE_EFFECTS((params[VIndex] = input_iter.template data<BIndex>()));
+            returned_array::call(
+                out, i, f, *reinterpret_cast<param_n_t<Index> *>(std::get<Index>(params))...);
+        }
+    }
+};
+
+template <typename Func, typename Return, typename... Args>
+vectorize_helper<Func, Return, Args...> vectorize_extractor(const Func &f, Return (*)(Args...)) {
+    return detail::vectorize_helper<Func, Return, Args...>(f);
+}
+
+template <typename T, int Flags>
+struct handle_type_name<array_t<T, Flags>> {
+    static constexpr auto name
+        = const_name("numpy.ndarray[") + npy_format_descriptor<T>::name + const_name("]");
+};
+
+PYBIND11_NAMESPACE_END(detail)
+
+// Vanilla pointer vectorizer:
+template <typename Return, typename... Args>
+detail::vectorize_helper<Return (*)(Args...), Return, Args...> vectorize(Return (*f)(Args...)) {
+    return detail::vectorize_helper<Return (*)(Args...), Return, Args...>(f);
+}
+
+// lambda vectorizer:
+template <typename Func, detail::enable_if_t<detail::is_lambda<Func>::value, int> = 0>
+auto vectorize(Func &&f)
+    -> decltype(detail::vectorize_extractor(std::forward<Func>(f),
+                                            (detail::function_signature_t<Func> *) nullptr)) {
+    return detail::vectorize_extractor(std::forward<Func>(f),
+                                       (detail::function_signature_t<Func> *) nullptr);
+}
+
+// Vectorize a class method (non-const):
+template <typename Return,
+          typename Class,
+          typename... Args,
+          typename Helper = detail::vectorize_helper<
+              decltype(std::mem_fn(std::declval<Return (Class::*)(Args...)>())),
+              Return,
+              Class *,
+              Args...>>
+Helper vectorize(Return (Class::*f)(Args...)) {
+    return Helper(std::mem_fn(f));
+}
+
+// Vectorize a class method (const):
+template <typename Return,
+          typename Class,
+          typename... Args,
+          typename Helper = detail::vectorize_helper<
+              decltype(std::mem_fn(std::declval<Return (Class::*)(Args...) const>())),
+              Return,
+              const Class *,
+              Args...>>
+Helper vectorize(Return (Class::*f)(Args...) const) {
+    return Helper(std::mem_fn(f));
+}
+
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

third-party/DPVO/DPViewer/pybind11/include/pybind11/operators.h

@@ -0,0 +1,201 @@
+/*
+    pybind11/operator.h: Metatemplates for operator overloading
+
+    Copyright (c) 2016 Wenzel Jakob <[email protected]>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "pybind11.h"
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+/// Enumeration with all supported operator types
+enum op_id : int {
+    op_add,
+    op_sub,
+    op_mul,
+    op_div,
+    op_mod,
+    op_divmod,
+    op_pow,
+    op_lshift,
+    op_rshift,
+    op_and,
+    op_xor,
+    op_or,
+    op_neg,
+    op_pos,
+    op_abs,
+    op_invert,
+    op_int,
+    op_long,
+    op_float,
+    op_str,
+    op_cmp,
+    op_gt,
+    op_ge,
+    op_lt,
+    op_le,
+    op_eq,
+    op_ne,
+    op_iadd,
+    op_isub,
+    op_imul,
+    op_idiv,
+    op_imod,
+    op_ilshift,
+    op_irshift,
+    op_iand,
+    op_ixor,
+    op_ior,
+    op_complex,
+    op_bool,
+    op_nonzero,
+    op_repr,
+    op_truediv,
+    op_itruediv,
+    op_hash
+};
+
+enum op_type : int {
+    op_l, /* base type on left */
+    op_r, /* base type on right */
+    op_u  /* unary operator */
+};
+
+struct self_t {};
+static const self_t self = self_t();
+
+/// Type for an unused type slot
+struct undefined_t {};
+
+/// Don't warn about an unused variable
+inline self_t __self() { return self; }
+
+/// base template of operator implementations
+template <op_id, op_type, typename B, typename L, typename R>
+struct op_impl {};
+
+/// Operator implementation generator
+template <op_id id, op_type ot, typename L, typename R>
+struct op_ {
+    template <typename Class, typename... Extra>
+    void execute(Class &cl, const Extra &...extra) const {
+        using Base = typename Class::type;
+        using L_type = conditional_t<std::is_same<L, self_t>::value, Base, L>;
+        using R_type = conditional_t<std::is_same<R, self_t>::value, Base, R>;
+        using op = op_impl<id, ot, Base, L_type, R_type>;
+        cl.def(op::name(), &op::execute, is_operator(), extra...);
+    }
+    template <typename Class, typename... Extra>
+    void execute_cast(Class &cl, const Extra &...extra) const {
+        using Base = typename Class::type;
+        using L_type = conditional_t<std::is_same<L, self_t>::value, Base, L>;
+        using R_type = conditional_t<std::is_same<R, self_t>::value, Base, R>;
+        using op = op_impl<id, ot, Base, L_type, R_type>;
+        cl.def(op::name(), &op::execute_cast, is_operator(), extra...);
+    }
+};
+
+#define PYBIND11_BINARY_OPERATOR(id, rid, op, expr)                                               \
+    template <typename B, typename L, typename R>                                                 \
+    struct op_impl<op_##id, op_l, B, L, R> {                                                      \
+        static char const *name() { return "__" #id "__"; }                                       \
+        static auto execute(const L &l, const R &r) -> decltype(expr) { return (expr); }          \
+        static B execute_cast(const L &l, const R &r) { return B(expr); }                         \
+    };                                                                                            \
+    template <typename B, typename L, typename R>                                                 \
+    struct op_impl<op_##id, op_r, B, L, R> {                                                      \
+        static char const *name() { return "__" #rid "__"; }                                      \
+        static auto execute(const R &r, const L &l) -> decltype(expr) { return (expr); }          \
+        static B execute_cast(const R &r, const L &l) { return B(expr); }                         \
+    };                                                                                            \
+    inline op_<op_##id, op_l, self_t, self_t> op(const self_t &, const self_t &) {                \
+        return op_<op_##id, op_l, self_t, self_t>();                                              \
+    }                                                                                             \
+    template <typename T>                                                                         \
+    op_<op_##id, op_l, self_t, T> op(const self_t &, const T &) {                                 \
+        return op_<op_##id, op_l, self_t, T>();                                                   \
+    }                                                                                             \
+    template <typename T>                                                                         \
+    op_<op_##id, op_r, T, self_t> op(const T &, const self_t &) {                                 \
+        return op_<op_##id, op_r, T, self_t>();                                                   \
+    }
+
+#define PYBIND11_INPLACE_OPERATOR(id, op, expr)                                                   \
+    template <typename B, typename L, typename R>                                                 \
+    struct op_impl<op_##id, op_l, B, L, R> {                                                      \
+        static char const *name() { return "__" #id "__"; }                                       \
+        static auto execute(L &l, const R &r) -> decltype(expr) { return expr; }                  \
+        static B execute_cast(L &l, const R &r) { return B(expr); }                               \
+    };                                                                                            \
+    template <typename T>                                                                         \
+    op_<op_##id, op_l, self_t, T> op(const self_t &, const T &) {                                 \
+        return op_<op_##id, op_l, self_t, T>();                                                   \
+    }
+
+#define PYBIND11_UNARY_OPERATOR(id, op, expr)                                                     \
+    template <typename B, typename L>                                                             \
+    struct op_impl<op_##id, op_u, B, L, undefined_t> {                                            \
+        static char const *name() { return "__" #id "__"; }                                       \
+        static auto execute(const L &l) -> decltype(expr) { return expr; }                        \
+        static B execute_cast(const L &l) { return B(expr); }                                     \
+    };                                                                                            \
+    inline op_<op_##id, op_u, self_t, undefined_t> op(const self_t &) {                           \
+        return op_<op_##id, op_u, self_t, undefined_t>();                                         \
+    }
+
+PYBIND11_BINARY_OPERATOR(sub, rsub, operator-, l - r)
+PYBIND11_BINARY_OPERATOR(add, radd, operator+, l + r)
+PYBIND11_BINARY_OPERATOR(mul, rmul, operator*, l *r)
+PYBIND11_BINARY_OPERATOR(truediv, rtruediv, operator/, l / r)
+PYBIND11_BINARY_OPERATOR(mod, rmod, operator%, l % r)
+PYBIND11_BINARY_OPERATOR(lshift, rlshift, operator<<, l << r)
+PYBIND11_BINARY_OPERATOR(rshift, rrshift, operator>>, l >> r)
+PYBIND11_BINARY_OPERATOR(and, rand, operator&, l &r)
+PYBIND11_BINARY_OPERATOR(xor, rxor, operator^, l ^ r)
+PYBIND11_BINARY_OPERATOR(eq, eq, operator==, l == r)
+PYBIND11_BINARY_OPERATOR(ne, ne, operator!=, l != r)
+PYBIND11_BINARY_OPERATOR(or, ror, operator|, l | r)
+PYBIND11_BINARY_OPERATOR(gt, lt, operator>, l > r)
+PYBIND11_BINARY_OPERATOR(ge, le, operator>=, l >= r)
+PYBIND11_BINARY_OPERATOR(lt, gt, operator<, l < r)
+PYBIND11_BINARY_OPERATOR(le, ge, operator<=, l <= r)
+// PYBIND11_BINARY_OPERATOR(pow,       rpow,         pow,          std::pow(l,  r))
+PYBIND11_INPLACE_OPERATOR(iadd, operator+=, l += r)
+PYBIND11_INPLACE_OPERATOR(isub, operator-=, l -= r)
+PYBIND11_INPLACE_OPERATOR(imul, operator*=, l *= r)
+PYBIND11_INPLACE_OPERATOR(itruediv, operator/=, l /= r)
+PYBIND11_INPLACE_OPERATOR(imod, operator%=, l %= r)
+PYBIND11_INPLACE_OPERATOR(ilshift, operator<<=, l <<= r)
+PYBIND11_INPLACE_OPERATOR(irshift, operator>>=, l >>= r)
+PYBIND11_INPLACE_OPERATOR(iand, operator&=, l &= r)
+PYBIND11_INPLACE_OPERATOR(ixor, operator^=, l ^= r)
+PYBIND11_INPLACE_OPERATOR(ior, operator|=, l |= r)
+PYBIND11_UNARY_OPERATOR(neg, operator-, -l)
+PYBIND11_UNARY_OPERATOR(pos, operator+, +l)
+// WARNING: This usage of `abs` should only be done for existing STL overloads.
+// Adding overloads directly in to the `std::` namespace is advised against:
+// https://en.cppreference.com/w/cpp/language/extending_std
+PYBIND11_UNARY_OPERATOR(abs, abs, std::abs(l))
+PYBIND11_UNARY_OPERATOR(hash, hash, std::hash<L>()(l))
+PYBIND11_UNARY_OPERATOR(invert, operator~, (~l))
+PYBIND11_UNARY_OPERATOR(bool, operator!, !!l)
+PYBIND11_UNARY_OPERATOR(int, int_, (int) l)
+PYBIND11_UNARY_OPERATOR(float, float_, (double) l)
+
+#undef PYBIND11_BINARY_OPERATOR
+#undef PYBIND11_INPLACE_OPERATOR
+#undef PYBIND11_UNARY_OPERATOR
+PYBIND11_NAMESPACE_END(detail)
+
+using detail::self;
+// Add named operators so that they are accessible via `py::`.
+using detail::hash;
+
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

third-party/DPVO/DPViewer/pybind11/include/pybind11/options.h

@@ -0,0 +1,76 @@
+/*
+    pybind11/options.h: global settings that are configurable at runtime.
+
+    Copyright (c) 2016 Wenzel Jakob <[email protected]>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "detail/common.h"
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+
+class options {
+public:
+    // Default RAII constructor, which leaves settings as they currently are.
+    options() : previous_state(global_state()) {}
+
+    // Class is non-copyable.
+    options(const options &) = delete;
+    options &operator=(const options &) = delete;
+
+    // Destructor, which restores settings that were in effect before.
+    ~options() { global_state() = previous_state; }
+
+    // Setter methods (affect the global state):
+
+    options &disable_user_defined_docstrings() & {
+        global_state().show_user_defined_docstrings = false;
+        return *this;
+    }
+
+    options &enable_user_defined_docstrings() & {
+        global_state().show_user_defined_docstrings = true;
+        return *this;
+    }
+
+    options &disable_function_signatures() & {
+        global_state().show_function_signatures = false;
+        return *this;
+    }
+
+    options &enable_function_signatures() & {
+        global_state().show_function_signatures = true;
+        return *this;
+    }
+
+    // Getter methods (return the global state):
+
+    static bool show_user_defined_docstrings() {
+        return global_state().show_user_defined_docstrings;
+    }
+
+    static bool show_function_signatures() { return global_state().show_function_signatures; }
+
+    // This type is not meant to be allocated on the heap.
+    void *operator new(size_t) = delete;
+
+private:
+    struct state {
+        bool show_user_defined_docstrings = true; //< Include user-supplied texts in docstrings.
+        bool show_function_signatures = true;     //< Include auto-generated function signatures
+                                                  //  in docstrings.
+    };
+
+    static state &global_state() {
+        static state instance;
+        return instance;
+    }
+
+    state previous_state;
+};
+
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

third-party/DPVO/DPViewer/pybind11/include/pybind11/pytypes.h

@@ -0,0 +1,2373 @@
+/*
+    pybind11/pytypes.h: Convenience wrapper classes for basic Python types
+
+    Copyright (c) 2016 Wenzel Jakob <[email protected]>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "detail/common.h"
+#include "buffer_info.h"
+
+#include <assert.h>
+#include <cstddef>
+#include <exception>
+#include <frameobject.h>
+#include <iterator>
+#include <memory>
+#include <string>
+#include <type_traits>
+#include <typeinfo>
+#include <utility>
+
+#if defined(PYBIND11_HAS_OPTIONAL)
+#    include <optional>
+#endif
+
+#ifdef PYBIND11_HAS_STRING_VIEW
+#    include <string_view>
+#endif
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+
+/* A few forward declarations */
+class handle;
+class object;
+class str;
+class iterator;
+class type;
+struct arg;
+struct arg_v;
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+class args_proxy;
+bool isinstance_generic(handle obj, const std::type_info &tp);
+
+// Accessor forward declarations
+template <typename Policy>
+class accessor;
+namespace accessor_policies {
+struct obj_attr;
+struct str_attr;
+struct generic_item;
+struct sequence_item;
+struct list_item;
+struct tuple_item;
+} // namespace accessor_policies
+using obj_attr_accessor = accessor<accessor_policies::obj_attr>;
+using str_attr_accessor = accessor<accessor_policies::str_attr>;
+using item_accessor = accessor<accessor_policies::generic_item>;
+using sequence_accessor = accessor<accessor_policies::sequence_item>;
+using list_accessor = accessor<accessor_policies::list_item>;
+using tuple_accessor = accessor<accessor_policies::tuple_item>;
+
+/// Tag and check to identify a class which implements the Python object API
+class pyobject_tag {};
+template <typename T>
+using is_pyobject = std::is_base_of<pyobject_tag, remove_reference_t<T>>;
+
+/** \rst
+    A mixin class which adds common functions to `handle`, `object` and various accessors.
+    The only requirement for `Derived` is to implement ``PyObject *Derived::ptr() const``.
+\endrst */
+template <typename Derived>
+class object_api : public pyobject_tag {
+    const Derived &derived() const { return static_cast<const Derived &>(*this); }
+
+public:
+    /** \rst
+        Return an iterator equivalent to calling ``iter()`` in Python. The object
+        must be a collection which supports the iteration protocol.
+    \endrst */
+    iterator begin() const;
+    /// Return a sentinel which ends iteration.
+    iterator end() const;
+
+    /** \rst
+        Return an internal functor to invoke the object's sequence protocol. Casting
+        the returned ``detail::item_accessor`` instance to a `handle` or `object`
+        subclass causes a corresponding call to ``__getitem__``. Assigning a `handle`
+        or `object` subclass causes a call to ``__setitem__``.
+    \endrst */
+    item_accessor operator[](handle key) const;
+    /// See above (the only difference is that the key's reference is stolen)
+    item_accessor operator[](object &&key) const;
+    /// See above (the only difference is that the key is provided as a string literal)
+    item_accessor operator[](const char *key) const;
+
+    /** \rst
+        Return an internal functor to access the object's attributes. Casting the
+        returned ``detail::obj_attr_accessor`` instance to a `handle` or `object`
+        subclass causes a corresponding call to ``getattr``. Assigning a `handle`
+        or `object` subclass causes a call to ``setattr``.
+    \endrst */
+    obj_attr_accessor attr(handle key) const;
+    /// See above (the only difference is that the key's reference is stolen)
+    obj_attr_accessor attr(object &&key) const;
+    /// See above (the only difference is that the key is provided as a string literal)
+    str_attr_accessor attr(const char *key) const;
+
+    /** \rst
+        Matches * unpacking in Python, e.g. to unpack arguments out of a ``tuple``
+        or ``list`` for a function call. Applying another * to the result yields
+        ** unpacking, e.g. to unpack a dict as function keyword arguments.
+        See :ref:`calling_python_functions`.
+    \endrst */
+    args_proxy operator*() const;
+
+    /// Check if the given item is contained within this object, i.e. ``item in obj``.
+    template <typename T>
+    bool contains(T &&item) const;
+
+    /** \rst
+        Assuming the Python object is a function or implements the ``__call__``
+        protocol, ``operator()`` invokes the underlying function, passing an
+        arbitrary set of parameters. The result is returned as a `object` and
+        may need to be converted back into a Python object using `handle::cast()`.
+
+        When some of the arguments cannot be converted to Python objects, the
+        function will throw a `cast_error` exception. When the Python function
+        call fails, a `error_already_set` exception is thrown.
+    \endrst */
+    template <return_value_policy policy = return_value_policy::automatic_reference,
+              typename... Args>
+    object operator()(Args &&...args) const;
+    template <return_value_policy policy = return_value_policy::automatic_reference,
+              typename... Args>
+    PYBIND11_DEPRECATED("call(...) was deprecated in favor of operator()(...)")
+    object call(Args &&...args) const;
+
+    /// Equivalent to ``obj is other`` in Python.
+    bool is(object_api const &other) const { return derived().ptr() == other.derived().ptr(); }
+    /// Equivalent to ``obj is None`` in Python.
+    bool is_none() const { return derived().ptr() == Py_None; }
+    /// Equivalent to obj == other in Python
+    bool equal(object_api const &other) const { return rich_compare(other, Py_EQ); }
+    bool not_equal(object_api const &other) const { return rich_compare(other, Py_NE); }
+    bool operator<(object_api const &other) const { return rich_compare(other, Py_LT); }
+    bool operator<=(object_api const &other) const { return rich_compare(other, Py_LE); }
+    bool operator>(object_api const &other) const { return rich_compare(other, Py_GT); }
+    bool operator>=(object_api const &other) const { return rich_compare(other, Py_GE); }
+
+    object operator-() const;
+    object operator~() const;
+    object operator+(object_api const &other) const;
+    object operator+=(object_api const &other) const;
+    object operator-(object_api const &other) const;
+    object operator-=(object_api const &other) const;
+    object operator*(object_api const &other) const;
+    object operator*=(object_api const &other) const;
+    object operator/(object_api const &other) const;
+    object operator/=(object_api const &other) const;
+    object operator|(object_api const &other) const;
+    object operator|=(object_api const &other) const;
+    object operator&(object_api const &other) const;
+    object operator&=(object_api const &other) const;
+    object operator^(object_api const &other) const;
+    object operator^=(object_api const &other) const;
+    object operator<<(object_api const &other) const;
+    object operator<<=(object_api const &other) const;
+    object operator>>(object_api const &other) const;
+    object operator>>=(object_api const &other) const;
+
+    PYBIND11_DEPRECATED("Use py::str(obj) instead")
+    pybind11::str str() const;
+
+    /// Get or set the object's docstring, i.e. ``obj.__doc__``.
+    str_attr_accessor doc() const;
+
+    /// Return the object's current reference count
+    int ref_count() const { return static_cast<int>(Py_REFCNT(derived().ptr())); }
+
+    // TODO PYBIND11_DEPRECATED(
+    //     "Call py::type::handle_of(h) or py::type::of(h) instead of h.get_type()")
+    handle get_type() const;
+
+private:
+    bool rich_compare(object_api const &other, int value) const;
+};
+
+PYBIND11_NAMESPACE_END(detail)
+
+#if !defined(PYBIND11_HANDLE_REF_DEBUG) && !defined(NDEBUG)
+#    define PYBIND11_HANDLE_REF_DEBUG
+#endif
+
+/** \rst
+    Holds a reference to a Python object (no reference counting)
+
+    The `handle` class is a thin wrapper around an arbitrary Python object (i.e. a
+    ``PyObject *`` in Python's C API). It does not perform any automatic reference
+    counting and merely provides a basic C++ interface to various Python API functions.
+
+    .. seealso::
+        The `object` class inherits from `handle` and adds automatic reference
+        counting features.
+\endrst */
+class handle : public detail::object_api<handle> {
+public:
+    /// The default constructor creates a handle with a ``nullptr``-valued pointer
+    handle() = default;
+    /// Creates a ``handle`` from the given raw Python object pointer
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    handle(PyObject *ptr) : m_ptr(ptr) {} // Allow implicit conversion from PyObject*
+
+    /// Return the underlying ``PyObject *`` pointer
+    PyObject *ptr() const { return m_ptr; }
+    PyObject *&ptr() { return m_ptr; }
+
+    /** \rst
+        Manually increase the reference count of the Python object. Usually, it is
+        preferable to use the `object` class which derives from `handle` and calls
+        this function automatically. Returns a reference to itself.
+    \endrst */
+    const handle &inc_ref() const & {
+#ifdef PYBIND11_HANDLE_REF_DEBUG
+        inc_ref_counter(1);
+#endif
+        Py_XINCREF(m_ptr);
+        return *this;
+    }
+
+    /** \rst
+        Manually decrease the reference count of the Python object. Usually, it is
+        preferable to use the `object` class which derives from `handle` and calls
+        this function automatically. Returns a reference to itself.
+    \endrst */
+    const handle &dec_ref() const & {
+        Py_XDECREF(m_ptr);
+        return *this;
+    }
+
+    /** \rst
+        Attempt to cast the Python object into the given C++ type. A `cast_error`
+        will be throw upon failure.
+    \endrst */
+    template <typename T>
+    T cast() const;
+    /// Return ``true`` when the `handle` wraps a valid Python object
+    explicit operator bool() const { return m_ptr != nullptr; }
+    /** \rst
+        Deprecated: Check that the underlying pointers are the same.
+        Equivalent to ``obj1 is obj2`` in Python.
+    \endrst */
+    PYBIND11_DEPRECATED("Use obj1.is(obj2) instead")
+    bool operator==(const handle &h) const { return m_ptr == h.m_ptr; }
+    PYBIND11_DEPRECATED("Use !obj1.is(obj2) instead")
+    bool operator!=(const handle &h) const { return m_ptr != h.m_ptr; }
+    PYBIND11_DEPRECATED("Use handle::operator bool() instead")
+    bool check() const { return m_ptr != nullptr; }
+
+protected:
+    PyObject *m_ptr = nullptr;
+
+#ifdef PYBIND11_HANDLE_REF_DEBUG
+private:
+    static std::size_t inc_ref_counter(std::size_t add) {
+        thread_local std::size_t counter = 0;
+        counter += add;
+        return counter;
+    }
+
+public:
+    static std::size_t inc_ref_counter() { return inc_ref_counter(0); }
+#endif
+};
+
+/** \rst
+    Holds a reference to a Python object (with reference counting)
+
+    Like `handle`, the `object` class is a thin wrapper around an arbitrary Python
+    object (i.e. a ``PyObject *`` in Python's C API). In contrast to `handle`, it
+    optionally increases the object's reference count upon construction, and it
+    *always* decreases the reference count when the `object` instance goes out of
+    scope and is destructed. When using `object` instances consistently, it is much
+    easier to get reference counting right at the first attempt.
+\endrst */
+class object : public handle {
+public:
+    object() = default;
+    PYBIND11_DEPRECATED("Use reinterpret_borrow<object>() or reinterpret_steal<object>()")
+    object(handle h, bool is_borrowed) : handle(h) {
+        if (is_borrowed) {
+            inc_ref();
+        }
+    }
+    /// Copy constructor; always increases the reference count
+    object(const object &o) : handle(o) { inc_ref(); }
+    /// Move constructor; steals the object from ``other`` and preserves its reference count
+    object(object &&other) noexcept : handle(other) { other.m_ptr = nullptr; }
+    /// Destructor; automatically calls `handle::dec_ref()`
+    ~object() { dec_ref(); }
+
+    /** \rst
+        Resets the internal pointer to ``nullptr`` without decreasing the
+        object's reference count. The function returns a raw handle to the original
+        Python object.
+    \endrst */
+    handle release() {
+        PyObject *tmp = m_ptr;
+        m_ptr = nullptr;
+        return handle(tmp);
+    }
+
+    object &operator=(const object &other) {
+        other.inc_ref();
+        // Use temporary variable to ensure `*this` remains valid while
+        // `Py_XDECREF` executes, in case `*this` is accessible from Python.
+        handle temp(m_ptr);
+        m_ptr = other.m_ptr;
+        temp.dec_ref();
+        return *this;
+    }
+
+    object &operator=(object &&other) noexcept {
+        if (this != &other) {
+            handle temp(m_ptr);
+            m_ptr = other.m_ptr;
+            other.m_ptr = nullptr;
+            temp.dec_ref();
+        }
+        return *this;
+    }
+
+    // Calling cast() on an object lvalue just copies (via handle::cast)
+    template <typename T>
+    T cast() const &;
+    // Calling on an object rvalue does a move, if needed and/or possible
+    template <typename T>
+    T cast() &&;
+
+protected:
+    // Tags for choosing constructors from raw PyObject *
+    struct borrowed_t {};
+    struct stolen_t {};
+
+    /// @cond BROKEN
+    template <typename T>
+    friend T reinterpret_borrow(handle);
+    template <typename T>
+    friend T reinterpret_steal(handle);
+    /// @endcond
+
+public:
+    // Only accessible from derived classes and the reinterpret_* functions
+    object(handle h, borrowed_t) : handle(h) { inc_ref(); }
+    object(handle h, stolen_t) : handle(h) {}
+};
+
+/** \rst
+    Declare that a `handle` or ``PyObject *`` is a certain type and borrow the reference.
+    The target type ``T`` must be `object` or one of its derived classes. The function
+    doesn't do any conversions or checks. It's up to the user to make sure that the
+    target type is correct.
+
+    .. code-block:: cpp
+
+        PyObject *p = PyList_GetItem(obj, index);
+        py::object o = reinterpret_borrow<py::object>(p);
+        // or
+        py::tuple t = reinterpret_borrow<py::tuple>(p); // <-- `p` must be already be a `tuple`
+\endrst */
+template <typename T>
+T reinterpret_borrow(handle h) {
+    return {h, object::borrowed_t{}};
+}
+
+/** \rst
+    Like `reinterpret_borrow`, but steals the reference.
+
+     .. code-block:: cpp
+
+        PyObject *p = PyObject_Str(obj);
+        py::str s = reinterpret_steal<py::str>(p); // <-- `p` must be already be a `str`
+\endrst */
+template <typename T>
+T reinterpret_steal(handle h) {
+    return {h, object::stolen_t{}};
+}
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+// Equivalent to obj.__class__.__name__ (or obj.__name__ if obj is a class).
+inline const char *obj_class_name(PyObject *obj) {
+    if (Py_TYPE(obj) == &PyType_Type) {
+        return reinterpret_cast<PyTypeObject *>(obj)->tp_name;
+    }
+    return Py_TYPE(obj)->tp_name;
+}
+
+std::string error_string();
+
+struct error_fetch_and_normalize {
+    // Immediate normalization is long-established behavior (starting with
+    // https://github.com/pybind/pybind11/commit/135ba8deafb8bf64a15b24d1513899eb600e2011
+    // from Sep 2016) and safest. Normalization could be deferred, but this could mask
+    // errors elsewhere, the performance gain is very minor in typical situations
+    // (usually the dominant bottleneck is EH unwinding), and the implementation here
+    // would be more complex.
+    explicit error_fetch_and_normalize(const char *called) {
+        PyErr_Fetch(&m_type.ptr(), &m_value.ptr(), &m_trace.ptr());
+        if (!m_type) {
+            pybind11_fail("Internal error: " + std::string(called)
+                          + " called while "
+                            "Python error indicator not set.");
+        }
+        const char *exc_type_name_orig = detail::obj_class_name(m_type.ptr());
+        if (exc_type_name_orig == nullptr) {
+            pybind11_fail("Internal error: " + std::string(called)
+                          + " failed to obtain the name "
+                            "of the original active exception type.");
+        }
+        m_lazy_error_string = exc_type_name_orig;
+        // PyErr_NormalizeException() may change the exception type if there are cascading
+        // failures. This can potentially be extremely confusing.
+        PyErr_NormalizeException(&m_type.ptr(), &m_value.ptr(), &m_trace.ptr());
+        if (m_type.ptr() == nullptr) {
+            pybind11_fail("Internal error: " + std::string(called)
+                          + " failed to normalize the "
+                            "active exception.");
+        }
+        const char *exc_type_name_norm = detail::obj_class_name(m_type.ptr());
+        if (exc_type_name_orig == nullptr) {
+            pybind11_fail("Internal error: " + std::string(called)
+                          + " failed to obtain the name "
+                            "of the normalized active exception type.");
+        }
+        if (exc_type_name_norm != m_lazy_error_string) {
+            std::string msg = std::string(called)
+                              + ": MISMATCH of original and normalized "
+                                "active exception types: ";
+            msg += "ORIGINAL ";
+            msg += m_lazy_error_string;
+            msg += " REPLACED BY ";
+            msg += exc_type_name_norm;
+            msg += ": " + format_value_and_trace();
+            pybind11_fail(msg);
+        }
+    }
+
+    error_fetch_and_normalize(const error_fetch_and_normalize &) = delete;
+    error_fetch_and_normalize(error_fetch_and_normalize &&) = delete;
+
+    std::string format_value_and_trace() const {
+        std::string result;
+        std::string message_error_string;
+        if (m_value) {
+            auto value_str = reinterpret_steal<object>(PyObject_Str(m_value.ptr()));
+            if (!value_str) {
+                message_error_string = detail::error_string();
+                result = "<MESSAGE UNAVAILABLE DUE TO ANOTHER EXCEPTION>";
+            } else {
+                result = value_str.cast<std::string>();
+            }
+        } else {
+            result = "<MESSAGE UNAVAILABLE>";
+        }
+        if (result.empty()) {
+            result = "<EMPTY MESSAGE>";
+        }
+
+        bool have_trace = false;
+        if (m_trace) {
+#if !defined(PYPY_VERSION)
+            auto *tb = reinterpret_cast<PyTracebackObject *>(m_trace.ptr());
+
+            // Get the deepest trace possible.
+            while (tb->tb_next) {
+                tb = tb->tb_next;
+            }
+
+            PyFrameObject *frame = tb->tb_frame;
+            Py_XINCREF(frame);
+            result += "\n\nAt:\n";
+            while (frame) {
+#    if PY_VERSION_HEX >= 0x030900B1
+                PyCodeObject *f_code = PyFrame_GetCode(frame);
+#    else
+                PyCodeObject *f_code = frame->f_code;
+                Py_INCREF(f_code);
+#    endif
+                int lineno = PyFrame_GetLineNumber(frame);
+                result += "  ";
+                result += handle(f_code->co_filename).cast<std::string>();
+                result += '(';
+                result += std::to_string(lineno);
+                result += "): ";
+                result += handle(f_code->co_name).cast<std::string>();
+                result += '\n';
+                Py_DECREF(f_code);
+#    if PY_VERSION_HEX >= 0x030900B1
+                auto *b_frame = PyFrame_GetBack(frame);
+#    else
+                auto *b_frame = frame->f_back;
+                Py_XINCREF(b_frame);
+#    endif
+                Py_DECREF(frame);
+                frame = b_frame;
+            }
+
+            have_trace = true;
+#endif //! defined(PYPY_VERSION)
+        }
+
+        if (!message_error_string.empty()) {
+            if (!have_trace) {
+                result += '\n';
+            }
+            result += "\nMESSAGE UNAVAILABLE DUE TO EXCEPTION: " + message_error_string;
+        }
+
+        return result;
+    }
+
+    std::string const &error_string() const {
+        if (!m_lazy_error_string_completed) {
+            m_lazy_error_string += ": " + format_value_and_trace();
+            m_lazy_error_string_completed = true;
+        }
+        return m_lazy_error_string;
+    }
+
+    void restore() {
+        if (m_restore_called) {
+            pybind11_fail("Internal error: pybind11::detail::error_fetch_and_normalize::restore() "
+                          "called a second time. ORIGINAL ERROR: "
+                          + error_string());
+        }
+        PyErr_Restore(m_type.inc_ref().ptr(), m_value.inc_ref().ptr(), m_trace.inc_ref().ptr());
+        m_restore_called = true;
+    }
+
+    bool matches(handle exc) const {
+        return (PyErr_GivenExceptionMatches(m_type.ptr(), exc.ptr()) != 0);
+    }
+
+    // Not protecting these for simplicity.
+    object m_type, m_value, m_trace;
+
+private:
+    // Only protecting invariants.
+    mutable std::string m_lazy_error_string;
+    mutable bool m_lazy_error_string_completed = false;
+    mutable bool m_restore_called = false;
+};
+
+inline std::string error_string() {
+    return error_fetch_and_normalize("pybind11::detail::error_string").error_string();
+}
+
+PYBIND11_NAMESPACE_END(detail)
+
+#if defined(_MSC_VER)
+#    pragma warning(push)
+#    pragma warning(disable : 4275 4251)
+//     warning C4275: An exported class was derived from a class that wasn't exported.
+//     Can be ignored when derived from a STL class.
+#endif
+/// Fetch and hold an error which was already set in Python.  An instance of this is typically
+/// thrown to propagate python-side errors back through C++ which can either be caught manually or
+/// else falls back to the function dispatcher (which then raises the captured error back to
+/// python).
+class PYBIND11_EXPORT_EXCEPTION error_already_set : public std::exception {
+public:
+    /// Fetches the current Python exception (using PyErr_Fetch()), which will clear the
+    /// current Python error indicator.
+    error_already_set()
+        : m_fetched_error{new detail::error_fetch_and_normalize("pybind11::error_already_set"),
+                          m_fetched_error_deleter} {}
+
+    /// The what() result is built lazily on demand.
+    /// WARNING: This member function needs to acquire the Python GIL. This can lead to
+    ///          crashes (undefined behavior) if the Python interpreter is finalizing.
+    const char *what() const noexcept override;
+
+    /// Restores the currently-held Python error (which will clear the Python error indicator first
+    /// if already set).
+    /// NOTE: This member function will always restore the normalized exception, which may or may
+    ///       not be the original Python exception.
+    /// WARNING: The GIL must be held when this member function is called!
+    void restore() { m_fetched_error->restore(); }
+
+    /// If it is impossible to raise the currently-held error, such as in a destructor, we can
+    /// write it out using Python's unraisable hook (`sys.unraisablehook`). The error context
+    /// should be some object whose `repr()` helps identify the location of the error. Python
+    /// already knows the type and value of the error, so there is no need to repeat that.
+    void discard_as_unraisable(object err_context) {
+        restore();
+        PyErr_WriteUnraisable(err_context.ptr());
+    }
+    /// An alternate version of `discard_as_unraisable()`, where a string provides information on
+    /// the location of the error. For example, `__func__` could be helpful.
+    /// WARNING: The GIL must be held when this member function is called!
+    void discard_as_unraisable(const char *err_context) {
+        discard_as_unraisable(reinterpret_steal<object>(PYBIND11_FROM_STRING(err_context)));
+    }
+
+    // Does nothing; provided for backwards compatibility.
+    PYBIND11_DEPRECATED("Use of error_already_set.clear() is deprecated")
+    void clear() {}
+
+    /// Check if the currently trapped error type matches the given Python exception class (or a
+    /// subclass thereof).  May also be passed a tuple to search for any exception class matches in
+    /// the given tuple.
+    bool matches(handle exc) const { return m_fetched_error->matches(exc); }
+
+    const object &type() const { return m_fetched_error->m_type; }
+    const object &value() const { return m_fetched_error->m_value; }
+    const object &trace() const { return m_fetched_error->m_trace; }
+
+private:
+    std::shared_ptr<detail::error_fetch_and_normalize> m_fetched_error;
+
+    /// WARNING: This custom deleter needs to acquire the Python GIL. This can lead to
+    ///          crashes (undefined behavior) if the Python interpreter is finalizing.
+    static void m_fetched_error_deleter(detail::error_fetch_and_normalize *raw_ptr);
+};
+#if defined(_MSC_VER)
+#    pragma warning(pop)
+#endif
+
+/// Replaces the current Python error indicator with the chosen error, performing a
+/// 'raise from' to indicate that the chosen error was caused by the original error.
+inline void raise_from(PyObject *type, const char *message) {
+    // Based on _PyErr_FormatVFromCause:
+    // https://github.com/python/cpython/blob/467ab194fc6189d9f7310c89937c51abeac56839/Python/errors.c#L405
+    // See https://github.com/pybind/pybind11/pull/2112 for details.
+    PyObject *exc = nullptr, *val = nullptr, *val2 = nullptr, *tb = nullptr;
+
+    assert(PyErr_Occurred());
+    PyErr_Fetch(&exc, &val, &tb);
+    PyErr_NormalizeException(&exc, &val, &tb);
+    if (tb != nullptr) {
+        PyException_SetTraceback(val, tb);
+        Py_DECREF(tb);
+    }
+    Py_DECREF(exc);
+    assert(!PyErr_Occurred());
+
+    PyErr_SetString(type, message);
+
+    PyErr_Fetch(&exc, &val2, &tb);
+    PyErr_NormalizeException(&exc, &val2, &tb);
+    Py_INCREF(val);
+    PyException_SetCause(val2, val);
+    PyException_SetContext(val2, val);
+    PyErr_Restore(exc, val2, tb);
+}
+
+/// Sets the current Python error indicator with the chosen error, performing a 'raise from'
+/// from the error contained in error_already_set to indicate that the chosen error was
+/// caused by the original error.
+inline void raise_from(error_already_set &err, PyObject *type, const char *message) {
+    err.restore();
+    raise_from(type, message);
+}
+
+/** \defgroup python_builtins const_name
+    Unless stated otherwise, the following C++ functions behave the same
+    as their Python counterparts.
+ */
+
+/** \ingroup python_builtins
+    \rst
+    Return true if ``obj`` is an instance of ``T``. Type ``T`` must be a subclass of
+    `object` or a class which was exposed to Python as ``py::class_<T>``.
+\endrst */
+template <typename T, detail::enable_if_t<std::is_base_of<object, T>::value, int> = 0>
+bool isinstance(handle obj) {
+    return T::check_(obj);
+}
+
+template <typename T, detail::enable_if_t<!std::is_base_of<object, T>::value, int> = 0>
+bool isinstance(handle obj) {
+    return detail::isinstance_generic(obj, typeid(T));
+}
+
+template <>
+inline bool isinstance<handle>(handle) = delete;
+template <>
+inline bool isinstance<object>(handle obj) {
+    return obj.ptr() != nullptr;
+}
+
+/// \ingroup python_builtins
+/// Return true if ``obj`` is an instance of the ``type``.
+inline bool isinstance(handle obj, handle type) {
+    const auto result = PyObject_IsInstance(obj.ptr(), type.ptr());
+    if (result == -1) {
+        throw error_already_set();
+    }
+    return result != 0;
+}
+
+/// \addtogroup python_builtins
+/// @{
+inline bool hasattr(handle obj, handle name) {
+    return PyObject_HasAttr(obj.ptr(), name.ptr()) == 1;
+}
+
+inline bool hasattr(handle obj, const char *name) {
+    return PyObject_HasAttrString(obj.ptr(), name) == 1;
+}
+
+inline void delattr(handle obj, handle name) {
+    if (PyObject_DelAttr(obj.ptr(), name.ptr()) != 0) {
+        throw error_already_set();
+    }
+}
+
+inline void delattr(handle obj, const char *name) {
+    if (PyObject_DelAttrString(obj.ptr(), name) != 0) {
+        throw error_already_set();
+    }
+}
+
+inline object getattr(handle obj, handle name) {
+    PyObject *result = PyObject_GetAttr(obj.ptr(), name.ptr());
+    if (!result) {
+        throw error_already_set();
+    }
+    return reinterpret_steal<object>(result);
+}
+
+inline object getattr(handle obj, const char *name) {
+    PyObject *result = PyObject_GetAttrString(obj.ptr(), name);
+    if (!result) {
+        throw error_already_set();
+    }
+    return reinterpret_steal<object>(result);
+}
+
+inline object getattr(handle obj, handle name, handle default_) {
+    if (PyObject *result = PyObject_GetAttr(obj.ptr(), name.ptr())) {
+        return reinterpret_steal<object>(result);
+    }
+    PyErr_Clear();
+    return reinterpret_borrow<object>(default_);
+}
+
+inline object getattr(handle obj, const char *name, handle default_) {
+    if (PyObject *result = PyObject_GetAttrString(obj.ptr(), name)) {
+        return reinterpret_steal<object>(result);
+    }
+    PyErr_Clear();
+    return reinterpret_borrow<object>(default_);
+}
+
+inline void setattr(handle obj, handle name, handle value) {
+    if (PyObject_SetAttr(obj.ptr(), name.ptr(), value.ptr()) != 0) {
+        throw error_already_set();
+    }
+}
+
+inline void setattr(handle obj, const char *name, handle value) {
+    if (PyObject_SetAttrString(obj.ptr(), name, value.ptr()) != 0) {
+        throw error_already_set();
+    }
+}
+
+inline ssize_t hash(handle obj) {
+    auto h = PyObject_Hash(obj.ptr());
+    if (h == -1) {
+        throw error_already_set();
+    }
+    return h;
+}
+
+/// @} python_builtins
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+inline handle get_function(handle value) {
+    if (value) {
+        if (PyInstanceMethod_Check(value.ptr())) {
+            value = PyInstanceMethod_GET_FUNCTION(value.ptr());
+        } else if (PyMethod_Check(value.ptr())) {
+            value = PyMethod_GET_FUNCTION(value.ptr());
+        }
+    }
+    return value;
+}
+
+// Reimplementation of python's dict helper functions to ensure that exceptions
+// aren't swallowed (see #2862)
+
+// copied from cpython _PyDict_GetItemStringWithError
+inline PyObject *dict_getitemstring(PyObject *v, const char *key) {
+    PyObject *kv = nullptr, *rv = nullptr;
+    kv = PyUnicode_FromString(key);
+    if (kv == nullptr) {
+        throw error_already_set();
+    }
+
+    rv = PyDict_GetItemWithError(v, kv);
+    Py_DECREF(kv);
+    if (rv == nullptr && PyErr_Occurred()) {
+        throw error_already_set();
+    }
+    return rv;
+}
+
+inline PyObject *dict_getitem(PyObject *v, PyObject *key) {
+    PyObject *rv = PyDict_GetItemWithError(v, key);
+    if (rv == nullptr && PyErr_Occurred()) {
+        throw error_already_set();
+    }
+    return rv;
+}
+
+// Helper aliases/functions to support implicit casting of values given to python
+// accessors/methods. When given a pyobject, this simply returns the pyobject as-is; for other C++
+// type, the value goes through pybind11::cast(obj) to convert it to an `object`.
+template <typename T, enable_if_t<is_pyobject<T>::value, int> = 0>
+auto object_or_cast(T &&o) -> decltype(std::forward<T>(o)) {
+    return std::forward<T>(o);
+}
+// The following casting version is implemented in cast.h:
+template <typename T, enable_if_t<!is_pyobject<T>::value, int> = 0>
+object object_or_cast(T &&o);
+// Match a PyObject*, which we want to convert directly to handle via its converting constructor
+inline handle object_or_cast(PyObject *ptr) { return ptr; }
+
+#if defined(_MSC_VER) && _MSC_VER < 1920
+#    pragma warning(push)
+#    pragma warning(disable : 4522) // warning C4522: multiple assignment operators specified
+#endif
+template <typename Policy>
+class accessor : public object_api<accessor<Policy>> {
+    using key_type = typename Policy::key_type;
+
+public:
+    accessor(handle obj, key_type key) : obj(obj), key(std::move(key)) {}
+    accessor(const accessor &) = default;
+    accessor(accessor &&) noexcept = default;
+
+    // accessor overload required to override default assignment operator (templates are not
+    // allowed to replace default compiler-generated assignments).
+    void operator=(const accessor &a) && { std::move(*this).operator=(handle(a)); }
+    void operator=(const accessor &a) & { operator=(handle(a)); }
+
+    template <typename T>
+    void operator=(T &&value) && {
+        Policy::set(obj, key, object_or_cast(std::forward<T>(value)));
+    }
+    template <typename T>
+    void operator=(T &&value) & {
+        get_cache() = ensure_object(object_or_cast(std::forward<T>(value)));
+    }
+
+    template <typename T = Policy>
+    PYBIND11_DEPRECATED(
+        "Use of obj.attr(...) as bool is deprecated in favor of pybind11::hasattr(obj, ...)")
+    explicit
+    operator enable_if_t<std::is_same<T, accessor_policies::str_attr>::value
+                             || std::is_same<T, accessor_policies::obj_attr>::value,
+                         bool>() const {
+        return hasattr(obj, key);
+    }
+    template <typename T = Policy>
+    PYBIND11_DEPRECATED("Use of obj[key] as bool is deprecated in favor of obj.contains(key)")
+    explicit
+    operator enable_if_t<std::is_same<T, accessor_policies::generic_item>::value, bool>() const {
+        return obj.contains(key);
+    }
+
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    operator object() const { return get_cache(); }
+    PyObject *ptr() const { return get_cache().ptr(); }
+    template <typename T>
+    T cast() const {
+        return get_cache().template cast<T>();
+    }
+
+private:
+    static object ensure_object(object &&o) { return std::move(o); }
+    static object ensure_object(handle h) { return reinterpret_borrow<object>(h); }
+
+    object &get_cache() const {
+        if (!cache) {
+            cache = Policy::get(obj, key);
+        }
+        return cache;
+    }
+
+private:
+    handle obj;
+    key_type key;
+    mutable object cache;
+};
+#if defined(_MSC_VER) && _MSC_VER < 1920
+#    pragma warning(pop)
+#endif
+
+PYBIND11_NAMESPACE_BEGIN(accessor_policies)
+struct obj_attr {
+    using key_type = object;
+    static object get(handle obj, handle key) { return getattr(obj, key); }
+    static void set(handle obj, handle key, handle val) { setattr(obj, key, val); }
+};
+
+struct str_attr {
+    using key_type = const char *;
+    static object get(handle obj, const char *key) { return getattr(obj, key); }
+    static void set(handle obj, const char *key, handle val) { setattr(obj, key, val); }
+};
+
+struct generic_item {
+    using key_type = object;
+
+    static object get(handle obj, handle key) {
+        PyObject *result = PyObject_GetItem(obj.ptr(), key.ptr());
+        if (!result) {
+            throw error_already_set();
+        }
+        return reinterpret_steal<object>(result);
+    }
+
+    static void set(handle obj, handle key, handle val) {
+        if (PyObject_SetItem(obj.ptr(), key.ptr(), val.ptr()) != 0) {
+            throw error_already_set();
+        }
+    }
+};
+
+struct sequence_item {
+    using key_type = size_t;
+
+    template <typename IdxType, detail::enable_if_t<std::is_integral<IdxType>::value, int> = 0>
+    static object get(handle obj, const IdxType &index) {
+        PyObject *result = PySequence_GetItem(obj.ptr(), ssize_t_cast(index));
+        if (!result) {
+            throw error_already_set();
+        }
+        return reinterpret_steal<object>(result);
+    }
+
+    template <typename IdxType, detail::enable_if_t<std::is_integral<IdxType>::value, int> = 0>
+    static void set(handle obj, const IdxType &index, handle val) {
+        // PySequence_SetItem does not steal a reference to 'val'
+        if (PySequence_SetItem(obj.ptr(), ssize_t_cast(index), val.ptr()) != 0) {
+            throw error_already_set();
+        }
+    }
+};
+
+struct list_item {
+    using key_type = size_t;
+
+    template <typename IdxType, detail::enable_if_t<std::is_integral<IdxType>::value, int> = 0>
+    static object get(handle obj, const IdxType &index) {
+        PyObject *result = PyList_GetItem(obj.ptr(), ssize_t_cast(index));
+        if (!result) {
+            throw error_already_set();
+        }
+        return reinterpret_borrow<object>(result);
+    }
+
+    template <typename IdxType, detail::enable_if_t<std::is_integral<IdxType>::value, int> = 0>
+    static void set(handle obj, const IdxType &index, handle val) {
+        // PyList_SetItem steals a reference to 'val'
+        if (PyList_SetItem(obj.ptr(), ssize_t_cast(index), val.inc_ref().ptr()) != 0) {
+            throw error_already_set();
+        }
+    }
+};
+
+struct tuple_item {
+    using key_type = size_t;
+
+    template <typename IdxType, detail::enable_if_t<std::is_integral<IdxType>::value, int> = 0>
+    static object get(handle obj, const IdxType &index) {
+        PyObject *result = PyTuple_GetItem(obj.ptr(), ssize_t_cast(index));
+        if (!result) {
+            throw error_already_set();
+        }
+        return reinterpret_borrow<object>(result);
+    }
+
+    template <typename IdxType, detail::enable_if_t<std::is_integral<IdxType>::value, int> = 0>
+    static void set(handle obj, const IdxType &index, handle val) {
+        // PyTuple_SetItem steals a reference to 'val'
+        if (PyTuple_SetItem(obj.ptr(), ssize_t_cast(index), val.inc_ref().ptr()) != 0) {
+            throw error_already_set();
+        }
+    }
+};
+PYBIND11_NAMESPACE_END(accessor_policies)
+
+/// STL iterator template used for tuple, list, sequence and dict
+template <typename Policy>
+class generic_iterator : public Policy {
+    using It = generic_iterator;
+
+public:
+    using difference_type = ssize_t;
+    using iterator_category = typename Policy::iterator_category;
+    using value_type = typename Policy::value_type;
+    using reference = typename Policy::reference;
+    using pointer = typename Policy::pointer;
+
+    generic_iterator() = default;
+    generic_iterator(handle seq, ssize_t index) : Policy(seq, index) {}
+
+    // NOLINTNEXTLINE(readability-const-return-type) // PR #3263
+    reference operator*() const { return Policy::dereference(); }
+    // NOLINTNEXTLINE(readability-const-return-type) // PR #3263
+    reference operator[](difference_type n) const { return *(*this + n); }
+    pointer operator->() const { return **this; }
+
+    It &operator++() {
+        Policy::increment();
+        return *this;
+    }
+    It operator++(int) {
+        auto copy = *this;
+        Policy::increment();
+        return copy;
+    }
+    It &operator--() {
+        Policy::decrement();
+        return *this;
+    }
+    It operator--(int) {
+        auto copy = *this;
+        Policy::decrement();
+        return copy;
+    }
+    It &operator+=(difference_type n) {
+        Policy::advance(n);
+        return *this;
+    }
+    It &operator-=(difference_type n) {
+        Policy::advance(-n);
+        return *this;
+    }
+
+    friend It operator+(const It &a, difference_type n) {
+        auto copy = a;
+        return copy += n;
+    }
+    friend It operator+(difference_type n, const It &b) { return b + n; }
+    friend It operator-(const It &a, difference_type n) {
+        auto copy = a;
+        return copy -= n;
+    }
+    friend difference_type operator-(const It &a, const It &b) { return a.distance_to(b); }
+
+    friend bool operator==(const It &a, const It &b) { return a.equal(b); }
+    friend bool operator!=(const It &a, const It &b) { return !(a == b); }
+    friend bool operator<(const It &a, const It &b) { return b - a > 0; }
+    friend bool operator>(const It &a, const It &b) { return b < a; }
+    friend bool operator>=(const It &a, const It &b) { return !(a < b); }
+    friend bool operator<=(const It &a, const It &b) { return !(a > b); }
+};
+
+PYBIND11_NAMESPACE_BEGIN(iterator_policies)
+/// Quick proxy class needed to implement ``operator->`` for iterators which can't return pointers
+template <typename T>
+struct arrow_proxy {
+    T value;
+
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    arrow_proxy(T &&value) noexcept : value(std::move(value)) {}
+    T *operator->() const { return &value; }
+};
+
+/// Lightweight iterator policy using just a simple pointer: see ``PySequence_Fast_ITEMS``
+class sequence_fast_readonly {
+protected:
+    using iterator_category = std::random_access_iterator_tag;
+    using value_type = handle;
+    using reference = const handle; // PR #3263
+    using pointer = arrow_proxy<const handle>;
+
+    sequence_fast_readonly(handle obj, ssize_t n) : ptr(PySequence_Fast_ITEMS(obj.ptr()) + n) {}
+
+    // NOLINTNEXTLINE(readability-const-return-type) // PR #3263
+    reference dereference() const { return *ptr; }
+    void increment() { ++ptr; }
+    void decrement() { --ptr; }
+    void advance(ssize_t n) { ptr += n; }
+    bool equal(const sequence_fast_readonly &b) const { return ptr == b.ptr; }
+    ssize_t distance_to(const sequence_fast_readonly &b) const { return ptr - b.ptr; }
+
+private:
+    PyObject **ptr;
+};
+
+/// Full read and write access using the sequence protocol: see ``detail::sequence_accessor``
+class sequence_slow_readwrite {
+protected:
+    using iterator_category = std::random_access_iterator_tag;
+    using value_type = object;
+    using reference = sequence_accessor;
+    using pointer = arrow_proxy<const sequence_accessor>;
+
+    sequence_slow_readwrite(handle obj, ssize_t index) : obj(obj), index(index) {}
+
+    reference dereference() const { return {obj, static_cast<size_t>(index)}; }
+    void increment() { ++index; }
+    void decrement() { --index; }
+    void advance(ssize_t n) { index += n; }
+    bool equal(const sequence_slow_readwrite &b) const { return index == b.index; }
+    ssize_t distance_to(const sequence_slow_readwrite &b) const { return index - b.index; }
+
+private:
+    handle obj;
+    ssize_t index;
+};
+
+/// Python's dictionary protocol permits this to be a forward iterator
+class dict_readonly {
+protected:
+    using iterator_category = std::forward_iterator_tag;
+    using value_type = std::pair<handle, handle>;
+    using reference = const value_type; // PR #3263
+    using pointer = arrow_proxy<const value_type>;
+
+    dict_readonly() = default;
+    dict_readonly(handle obj, ssize_t pos) : obj(obj), pos(pos) { increment(); }
+
+    // NOLINTNEXTLINE(readability-const-return-type) // PR #3263
+    reference dereference() const { return {key, value}; }
+    void increment() {
+        if (PyDict_Next(obj.ptr(), &pos, &key, &value) == 0) {
+            pos = -1;
+        }
+    }
+    bool equal(const dict_readonly &b) const { return pos == b.pos; }
+
+private:
+    handle obj;
+    PyObject *key = nullptr, *value = nullptr;
+    ssize_t pos = -1;
+};
+PYBIND11_NAMESPACE_END(iterator_policies)
+
+#if !defined(PYPY_VERSION)
+using tuple_iterator = generic_iterator<iterator_policies::sequence_fast_readonly>;
+using list_iterator = generic_iterator<iterator_policies::sequence_fast_readonly>;
+#else
+using tuple_iterator = generic_iterator<iterator_policies::sequence_slow_readwrite>;
+using list_iterator = generic_iterator<iterator_policies::sequence_slow_readwrite>;
+#endif
+
+using sequence_iterator = generic_iterator<iterator_policies::sequence_slow_readwrite>;
+using dict_iterator = generic_iterator<iterator_policies::dict_readonly>;
+
+inline bool PyIterable_Check(PyObject *obj) {
+    PyObject *iter = PyObject_GetIter(obj);
+    if (iter) {
+        Py_DECREF(iter);
+        return true;
+    }
+    PyErr_Clear();
+    return false;
+}
+
+inline bool PyNone_Check(PyObject *o) { return o == Py_None; }
+inline bool PyEllipsis_Check(PyObject *o) { return o == Py_Ellipsis; }
+
+#ifdef PYBIND11_STR_LEGACY_PERMISSIVE
+inline bool PyUnicode_Check_Permissive(PyObject *o) {
+    return PyUnicode_Check(o) || PYBIND11_BYTES_CHECK(o);
+}
+#    define PYBIND11_STR_CHECK_FUN detail::PyUnicode_Check_Permissive
+#else
+#    define PYBIND11_STR_CHECK_FUN PyUnicode_Check
+#endif
+
+inline bool PyStaticMethod_Check(PyObject *o) { return o->ob_type == &PyStaticMethod_Type; }
+
+class kwargs_proxy : public handle {
+public:
+    explicit kwargs_proxy(handle h) : handle(h) {}
+};
+
+class args_proxy : public handle {
+public:
+    explicit args_proxy(handle h) : handle(h) {}
+    kwargs_proxy operator*() const { return kwargs_proxy(*this); }
+};
+
+/// Python argument categories (using PEP 448 terms)
+template <typename T>
+using is_keyword = std::is_base_of<arg, T>;
+template <typename T>
+using is_s_unpacking = std::is_same<args_proxy, T>; // * unpacking
+template <typename T>
+using is_ds_unpacking = std::is_same<kwargs_proxy, T>; // ** unpacking
+template <typename T>
+using is_positional = satisfies_none_of<T, is_keyword, is_s_unpacking, is_ds_unpacking>;
+template <typename T>
+using is_keyword_or_ds = satisfies_any_of<T, is_keyword, is_ds_unpacking>;
+
+// Call argument collector forward declarations
+template <return_value_policy policy = return_value_policy::automatic_reference>
+class simple_collector;
+template <return_value_policy policy = return_value_policy::automatic_reference>
+class unpacking_collector;
+
+PYBIND11_NAMESPACE_END(detail)
+
+// TODO: After the deprecated constructors are removed, this macro can be simplified by
+//       inheriting ctors: `using Parent::Parent`. It's not an option right now because
+//       the `using` statement triggers the parent deprecation warning even if the ctor
+//       isn't even used.
+#define PYBIND11_OBJECT_COMMON(Name, Parent, CheckFun)                                            \
+public:                                                                                           \
+    PYBIND11_DEPRECATED("Use reinterpret_borrow<" #Name ">() or reinterpret_steal<" #Name ">()")  \
+    Name(handle h, bool is_borrowed)                                                              \
+        : Parent(is_borrowed ? Parent(h, borrowed_t{}) : Parent(h, stolen_t{})) {}                \
+    Name(handle h, borrowed_t) : Parent(h, borrowed_t{}) {}                                       \
+    Name(handle h, stolen_t) : Parent(h, stolen_t{}) {}                                           \
+    PYBIND11_DEPRECATED("Use py::isinstance<py::python_type>(obj) instead")                       \
+    bool check() const { return m_ptr != nullptr && (CheckFun(m_ptr) != 0); }                     \
+    static bool check_(handle h) { return h.ptr() != nullptr && CheckFun(h.ptr()); }              \
+    template <typename Policy_> /* NOLINTNEXTLINE(google-explicit-constructor) */                 \
+    Name(const ::pybind11::detail::accessor<Policy_> &a) : Name(object(a)) {}
+
+#define PYBIND11_OBJECT_CVT(Name, Parent, CheckFun, ConvertFun)                                   \
+    PYBIND11_OBJECT_COMMON(Name, Parent, CheckFun)                                                \
+    /* This is deliberately not 'explicit' to allow implicit conversion from object: */           \
+    /* NOLINTNEXTLINE(google-explicit-constructor) */                                             \
+    Name(const object &o)                                                                         \
+        : Parent(check_(o) ? o.inc_ref().ptr() : ConvertFun(o.ptr()), stolen_t{}) {               \
+        if (!m_ptr)                                                                               \
+            throw ::pybind11::error_already_set();                                                \
+    }                                                                                             \
+    /* NOLINTNEXTLINE(google-explicit-constructor) */                                             \
+    Name(object &&o) : Parent(check_(o) ? o.release().ptr() : ConvertFun(o.ptr()), stolen_t{}) {  \
+        if (!m_ptr)                                                                               \
+            throw ::pybind11::error_already_set();                                                \
+    }
+
+#define PYBIND11_OBJECT_CVT_DEFAULT(Name, Parent, CheckFun, ConvertFun)                           \
+    PYBIND11_OBJECT_CVT(Name, Parent, CheckFun, ConvertFun)                                       \
+    Name() : Parent() {}
+
+#define PYBIND11_OBJECT_CHECK_FAILED(Name, o_ptr)                                                 \
+    ::pybind11::type_error("Object of type '"                                                     \
+                           + ::pybind11::detail::get_fully_qualified_tp_name(Py_TYPE(o_ptr))      \
+                           + "' is not an instance of '" #Name "'")
+
+#define PYBIND11_OBJECT(Name, Parent, CheckFun)                                                   \
+    PYBIND11_OBJECT_COMMON(Name, Parent, CheckFun)                                                \
+    /* This is deliberately not 'explicit' to allow implicit conversion from object: */           \
+    /* NOLINTNEXTLINE(google-explicit-constructor) */                                             \
+    Name(const object &o) : Parent(o) {                                                           \
+        if (m_ptr && !check_(m_ptr))                                                              \
+            throw PYBIND11_OBJECT_CHECK_FAILED(Name, m_ptr);                                      \
+    }                                                                                             \
+    /* NOLINTNEXTLINE(google-explicit-constructor) */                                             \
+    Name(object &&o) : Parent(std::move(o)) {                                                     \
+        if (m_ptr && !check_(m_ptr))                                                              \
+            throw PYBIND11_OBJECT_CHECK_FAILED(Name, m_ptr);                                      \
+    }
+
+#define PYBIND11_OBJECT_DEFAULT(Name, Parent, CheckFun)                                           \
+    PYBIND11_OBJECT(Name, Parent, CheckFun)                                                       \
+    Name() : Parent() {}
+
+/// \addtogroup pytypes
+/// @{
+
+/** \rst
+    Wraps a Python iterator so that it can also be used as a C++ input iterator
+
+    Caveat: copying an iterator does not (and cannot) clone the internal
+    state of the Python iterable. This also applies to the post-increment
+    operator. This iterator should only be used to retrieve the current
+    value using ``operator*()``.
+\endrst */
+class iterator : public object {
+public:
+    using iterator_category = std::input_iterator_tag;
+    using difference_type = ssize_t;
+    using value_type = handle;
+    using reference = const handle; // PR #3263
+    using pointer = const handle *;
+
+    PYBIND11_OBJECT_DEFAULT(iterator, object, PyIter_Check)
+
+    iterator &operator++() {
+        advance();
+        return *this;
+    }
+
+    iterator operator++(int) {
+        auto rv = *this;
+        advance();
+        return rv;
+    }
+
+    // NOLINTNEXTLINE(readability-const-return-type) // PR #3263
+    reference operator*() const {
+        if (m_ptr && !value.ptr()) {
+            auto &self = const_cast<iterator &>(*this);
+            self.advance();
+        }
+        return value;
+    }
+
+    pointer operator->() const {
+        operator*();
+        return &value;
+    }
+
+    /** \rst
+         The value which marks the end of the iteration. ``it == iterator::sentinel()``
+         is equivalent to catching ``StopIteration`` in Python.
+
+         .. code-block:: cpp
+
+             void foo(py::iterator it) {
+                 while (it != py::iterator::sentinel()) {
+                    // use `*it`
+                    ++it;
+                 }
+             }
+    \endrst */
+    static iterator sentinel() { return {}; }
+
+    friend bool operator==(const iterator &a, const iterator &b) { return a->ptr() == b->ptr(); }
+    friend bool operator!=(const iterator &a, const iterator &b) { return a->ptr() != b->ptr(); }
+
+private:
+    void advance() {
+        value = reinterpret_steal<object>(PyIter_Next(m_ptr));
+        if (PyErr_Occurred()) {
+            throw error_already_set();
+        }
+    }
+
+private:
+    object value = {};
+};
+
+class type : public object {
+public:
+    PYBIND11_OBJECT(type, object, PyType_Check)
+
+    /// Return a type handle from a handle or an object
+    static handle handle_of(handle h) { return handle((PyObject *) Py_TYPE(h.ptr())); }
+
+    /// Return a type object from a handle or an object
+    static type of(handle h) { return type(type::handle_of(h), borrowed_t{}); }
+
+    // Defined in pybind11/cast.h
+    /// Convert C++ type to handle if previously registered. Does not convert
+    /// standard types, like int, float. etc. yet.
+    /// See https://github.com/pybind/pybind11/issues/2486
+    template <typename T>
+    static handle handle_of();
+
+    /// Convert C++ type to type if previously registered. Does not convert
+    /// standard types, like int, float. etc. yet.
+    /// See https://github.com/pybind/pybind11/issues/2486
+    template <typename T>
+    static type of() {
+        return type(type::handle_of<T>(), borrowed_t{});
+    }
+};
+
+class iterable : public object {
+public:
+    PYBIND11_OBJECT_DEFAULT(iterable, object, detail::PyIterable_Check)
+};
+
+class bytes;
+
+class str : public object {
+public:
+    PYBIND11_OBJECT_CVT(str, object, PYBIND11_STR_CHECK_FUN, raw_str)
+
+    template <typename SzType, detail::enable_if_t<std::is_integral<SzType>::value, int> = 0>
+    str(const char *c, const SzType &n)
+        : object(PyUnicode_FromStringAndSize(c, ssize_t_cast(n)), stolen_t{}) {
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate string object!");
+        }
+    }
+
+    // 'explicit' is explicitly omitted from the following constructors to allow implicit
+    // conversion to py::str from C++ string-like objects
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    str(const char *c = "") : object(PyUnicode_FromString(c), stolen_t{}) {
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate string object!");
+        }
+    }
+
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    str(const std::string &s) : str(s.data(), s.size()) {}
+
+#ifdef PYBIND11_HAS_STRING_VIEW
+    // enable_if is needed to avoid "ambiguous conversion" errors (see PR #3521).
+    template <typename T, detail::enable_if_t<std::is_same<T, std::string_view>::value, int> = 0>
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    str(T s) : str(s.data(), s.size()) {}
+
+#    ifdef PYBIND11_HAS_U8STRING
+    // reinterpret_cast here is safe (C++20 guarantees char8_t has the same size/alignment as char)
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    str(std::u8string_view s) : str(reinterpret_cast<const char *>(s.data()), s.size()) {}
+#    endif
+
+#endif
+
+    explicit str(const bytes &b);
+
+    /** \rst
+        Return a string representation of the object. This is analogous to
+        the ``str()`` function in Python.
+    \endrst */
+    explicit str(handle h) : object(raw_str(h.ptr()), stolen_t{}) {
+        if (!m_ptr) {
+            throw error_already_set();
+        }
+    }
+
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    operator std::string() const {
+        object temp = *this;
+        if (PyUnicode_Check(m_ptr)) {
+            temp = reinterpret_steal<object>(PyUnicode_AsUTF8String(m_ptr));
+            if (!temp) {
+                throw error_already_set();
+            }
+        }
+        char *buffer = nullptr;
+        ssize_t length = 0;
+        if (PyBytes_AsStringAndSize(temp.ptr(), &buffer, &length) != 0) {
+            throw error_already_set();
+        }
+        return std::string(buffer, (size_t) length);
+    }
+
+    template <typename... Args>
+    str format(Args &&...args) const {
+        return attr("format")(std::forward<Args>(args)...);
+    }
+
+private:
+    /// Return string representation -- always returns a new reference, even if already a str
+    static PyObject *raw_str(PyObject *op) {
+        PyObject *str_value = PyObject_Str(op);
+        return str_value;
+    }
+};
+/// @} pytypes
+
+inline namespace literals {
+/** \rst
+    String literal version of `str`
+ \endrst */
+inline str operator"" _s(const char *s, size_t size) { return {s, size}; }
+} // namespace literals
+
+/// \addtogroup pytypes
+/// @{
+class bytes : public object {
+public:
+    PYBIND11_OBJECT(bytes, object, PYBIND11_BYTES_CHECK)
+
+    // Allow implicit conversion:
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    bytes(const char *c = "") : object(PYBIND11_BYTES_FROM_STRING(c), stolen_t{}) {
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate bytes object!");
+        }
+    }
+
+    template <typename SzType, detail::enable_if_t<std::is_integral<SzType>::value, int> = 0>
+    bytes(const char *c, const SzType &n)
+        : object(PYBIND11_BYTES_FROM_STRING_AND_SIZE(c, ssize_t_cast(n)), stolen_t{}) {
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate bytes object!");
+        }
+    }
+
+    // Allow implicit conversion:
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    bytes(const std::string &s) : bytes(s.data(), s.size()) {}
+
+    explicit bytes(const pybind11::str &s);
+
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    operator std::string() const { return string_op<std::string>(); }
+
+#ifdef PYBIND11_HAS_STRING_VIEW
+    // enable_if is needed to avoid "ambiguous conversion" errors (see PR #3521).
+    template <typename T, detail::enable_if_t<std::is_same<T, std::string_view>::value, int> = 0>
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    bytes(T s) : bytes(s.data(), s.size()) {}
+
+    // Obtain a string view that views the current `bytes` buffer value.  Note that this is only
+    // valid so long as the `bytes` instance remains alive and so generally should not outlive the
+    // lifetime of the `bytes` instance.
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    operator std::string_view() const { return string_op<std::string_view>(); }
+#endif
+private:
+    template <typename T>
+    T string_op() const {
+        char *buffer = nullptr;
+        ssize_t length = 0;
+        if (PyBytes_AsStringAndSize(m_ptr, &buffer, &length) != 0) {
+            throw error_already_set();
+        }
+        return {buffer, static_cast<size_t>(length)};
+    }
+};
+// Note: breathe >= 4.17.0 will fail to build docs if the below two constructors
+// are included in the doxygen group; close here and reopen after as a workaround
+/// @} pytypes
+
+inline bytes::bytes(const pybind11::str &s) {
+    object temp = s;
+    if (PyUnicode_Check(s.ptr())) {
+        temp = reinterpret_steal<object>(PyUnicode_AsUTF8String(s.ptr()));
+        if (!temp) {
+            throw error_already_set();
+        }
+    }
+    char *buffer = nullptr;
+    ssize_t length = 0;
+    if (PyBytes_AsStringAndSize(temp.ptr(), &buffer, &length) != 0) {
+        throw error_already_set();
+    }
+    auto obj = reinterpret_steal<object>(PYBIND11_BYTES_FROM_STRING_AND_SIZE(buffer, length));
+    if (!obj) {
+        pybind11_fail("Could not allocate bytes object!");
+    }
+    m_ptr = obj.release().ptr();
+}
+
+inline str::str(const bytes &b) {
+    char *buffer = nullptr;
+    ssize_t length = 0;
+    if (PyBytes_AsStringAndSize(b.ptr(), &buffer, &length) != 0) {
+        throw error_already_set();
+    }
+    auto obj = reinterpret_steal<object>(PyUnicode_FromStringAndSize(buffer, length));
+    if (!obj) {
+        pybind11_fail("Could not allocate string object!");
+    }
+    m_ptr = obj.release().ptr();
+}
+
+/// \addtogroup pytypes
+/// @{
+class bytearray : public object {
+public:
+    PYBIND11_OBJECT_CVT(bytearray, object, PyByteArray_Check, PyByteArray_FromObject)
+
+    template <typename SzType, detail::enable_if_t<std::is_integral<SzType>::value, int> = 0>
+    bytearray(const char *c, const SzType &n)
+        : object(PyByteArray_FromStringAndSize(c, ssize_t_cast(n)), stolen_t{}) {
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate bytearray object!");
+        }
+    }
+
+    bytearray() : bytearray("", 0) {}
+
+    explicit bytearray(const std::string &s) : bytearray(s.data(), s.size()) {}
+
+    size_t size() const { return static_cast<size_t>(PyByteArray_Size(m_ptr)); }
+
+    explicit operator std::string() const {
+        char *buffer = PyByteArray_AS_STRING(m_ptr);
+        ssize_t size = PyByteArray_GET_SIZE(m_ptr);
+        return std::string(buffer, static_cast<size_t>(size));
+    }
+};
+// Note: breathe >= 4.17.0 will fail to build docs if the below two constructors
+// are included in the doxygen group; close here and reopen after as a workaround
+/// @} pytypes
+
+/// \addtogroup pytypes
+/// @{
+class none : public object {
+public:
+    PYBIND11_OBJECT(none, object, detail::PyNone_Check)
+    none() : object(Py_None, borrowed_t{}) {}
+};
+
+class ellipsis : public object {
+public:
+    PYBIND11_OBJECT(ellipsis, object, detail::PyEllipsis_Check)
+    ellipsis() : object(Py_Ellipsis, borrowed_t{}) {}
+};
+
+class bool_ : public object {
+public:
+    PYBIND11_OBJECT_CVT(bool_, object, PyBool_Check, raw_bool)
+    bool_() : object(Py_False, borrowed_t{}) {}
+    // Allow implicit conversion from and to `bool`:
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    bool_(bool value) : object(value ? Py_True : Py_False, borrowed_t{}) {}
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    operator bool() const { return (m_ptr != nullptr) && PyLong_AsLong(m_ptr) != 0; }
+
+private:
+    /// Return the truth value of an object -- always returns a new reference
+    static PyObject *raw_bool(PyObject *op) {
+        const auto value = PyObject_IsTrue(op);
+        if (value == -1) {
+            return nullptr;
+        }
+        return handle(value != 0 ? Py_True : Py_False).inc_ref().ptr();
+    }
+};
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+// Converts a value to the given unsigned type.  If an error occurs, you get back (Unsigned) -1;
+// otherwise you get back the unsigned long or unsigned long long value cast to (Unsigned).
+// (The distinction is critically important when casting a returned -1 error value to some other
+// unsigned type: (A)-1 != (B)-1 when A and B are unsigned types of different sizes).
+template <typename Unsigned>
+Unsigned as_unsigned(PyObject *o) {
+    if (PYBIND11_SILENCE_MSVC_C4127(sizeof(Unsigned) <= sizeof(unsigned long))) {
+        unsigned long v = PyLong_AsUnsignedLong(o);
+        return v == (unsigned long) -1 && PyErr_Occurred() ? (Unsigned) -1 : (Unsigned) v;
+    }
+    unsigned long long v = PyLong_AsUnsignedLongLong(o);
+    return v == (unsigned long long) -1 && PyErr_Occurred() ? (Unsigned) -1 : (Unsigned) v;
+}
+PYBIND11_NAMESPACE_END(detail)
+
+class int_ : public object {
+public:
+    PYBIND11_OBJECT_CVT(int_, object, PYBIND11_LONG_CHECK, PyNumber_Long)
+    int_() : object(PyLong_FromLong(0), stolen_t{}) {}
+    // Allow implicit conversion from C++ integral types:
+    template <typename T, detail::enable_if_t<std::is_integral<T>::value, int> = 0>
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    int_(T value) {
+        if (PYBIND11_SILENCE_MSVC_C4127(sizeof(T) <= sizeof(long))) {
+            if (std::is_signed<T>::value) {
+                m_ptr = PyLong_FromLong((long) value);
+            } else {
+                m_ptr = PyLong_FromUnsignedLong((unsigned long) value);
+            }
+        } else {
+            if (std::is_signed<T>::value) {
+                m_ptr = PyLong_FromLongLong((long long) value);
+            } else {
+                m_ptr = PyLong_FromUnsignedLongLong((unsigned long long) value);
+            }
+        }
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate int object!");
+        }
+    }
+
+    template <typename T, detail::enable_if_t<std::is_integral<T>::value, int> = 0>
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    operator T() const {
+        return std::is_unsigned<T>::value  ? detail::as_unsigned<T>(m_ptr)
+               : sizeof(T) <= sizeof(long) ? (T) PyLong_AsLong(m_ptr)
+                                           : (T) PYBIND11_LONG_AS_LONGLONG(m_ptr);
+    }
+};
+
+class float_ : public object {
+public:
+    PYBIND11_OBJECT_CVT(float_, object, PyFloat_Check, PyNumber_Float)
+    // Allow implicit conversion from float/double:
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    float_(float value) : object(PyFloat_FromDouble((double) value), stolen_t{}) {
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate float object!");
+        }
+    }
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    float_(double value = .0) : object(PyFloat_FromDouble((double) value), stolen_t{}) {
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate float object!");
+        }
+    }
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    operator float() const { return (float) PyFloat_AsDouble(m_ptr); }
+    // NOLINTNEXTLINE(google-explicit-constructor)
+    operator double() const { return (double) PyFloat_AsDouble(m_ptr); }
+};
+
+class weakref : public object {
+public:
+    PYBIND11_OBJECT_CVT_DEFAULT(weakref, object, PyWeakref_Check, raw_weakref)
+    explicit weakref(handle obj, handle callback = {})
+        : object(PyWeakref_NewRef(obj.ptr(), callback.ptr()), stolen_t{}) {
+        if (!m_ptr) {
+            if (PyErr_Occurred()) {
+                throw error_already_set();
+            }
+            pybind11_fail("Could not allocate weak reference!");
+        }
+    }
+
+private:
+    static PyObject *raw_weakref(PyObject *o) { return PyWeakref_NewRef(o, nullptr); }
+};
+
+class slice : public object {
+public:
+    PYBIND11_OBJECT_DEFAULT(slice, object, PySlice_Check)
+    slice(handle start, handle stop, handle step)
+        : object(PySlice_New(start.ptr(), stop.ptr(), step.ptr()), stolen_t{}) {
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate slice object!");
+        }
+    }
+
+#ifdef PYBIND11_HAS_OPTIONAL
+    slice(std::optional<ssize_t> start, std::optional<ssize_t> stop, std::optional<ssize_t> step)
+        : slice(index_to_object(start), index_to_object(stop), index_to_object(step)) {}
+#else
+    slice(ssize_t start_, ssize_t stop_, ssize_t step_)
+        : slice(int_(start_), int_(stop_), int_(step_)) {}
+#endif
+
+    bool
+    compute(size_t length, size_t *start, size_t *stop, size_t *step, size_t *slicelength) const {
+        return PySlice_GetIndicesEx((PYBIND11_SLICE_OBJECT *) m_ptr,
+                                    (ssize_t) length,
+                                    (ssize_t *) start,
+                                    (ssize_t *) stop,
+                                    (ssize_t *) step,
+                                    (ssize_t *) slicelength)
+               == 0;
+    }
+    bool compute(
+        ssize_t length, ssize_t *start, ssize_t *stop, ssize_t *step, ssize_t *slicelength) const {
+        return PySlice_GetIndicesEx(
+                   (PYBIND11_SLICE_OBJECT *) m_ptr, length, start, stop, step, slicelength)
+               == 0;
+    }
+
+private:
+    template <typename T>
+    static object index_to_object(T index) {
+        return index ? object(int_(*index)) : object(none());
+    }
+};
+
+class capsule : public object {
+public:
+    PYBIND11_OBJECT_DEFAULT(capsule, object, PyCapsule_CheckExact)
+    PYBIND11_DEPRECATED("Use reinterpret_borrow<capsule>() or reinterpret_steal<capsule>()")
+    capsule(PyObject *ptr, bool is_borrowed)
+        : object(is_borrowed ? object(ptr, borrowed_t{}) : object(ptr, stolen_t{})) {}
+
+    explicit capsule(const void *value,
+                     const char *name = nullptr,
+                     void (*destructor)(PyObject *) = nullptr)
+        : object(PyCapsule_New(const_cast<void *>(value), name, destructor), stolen_t{}) {
+        if (!m_ptr) {
+            throw error_already_set();
+        }
+    }
+
+    PYBIND11_DEPRECATED("Please pass a destructor that takes a void pointer as input")
+    capsule(const void *value, void (*destruct)(PyObject *))
+        : object(PyCapsule_New(const_cast<void *>(value), nullptr, destruct), stolen_t{}) {
+        if (!m_ptr) {
+            throw error_already_set();
+        }
+    }
+
+    capsule(const void *value, void (*destructor)(void *)) {
+        m_ptr = PyCapsule_New(const_cast<void *>(value), nullptr, [](PyObject *o) {
+            // guard if destructor called while err indicator is set
+            error_scope error_guard;
+            auto destructor = reinterpret_cast<void (*)(void *)>(PyCapsule_GetContext(o));
+            if (destructor == nullptr) {
+                if (PyErr_Occurred()) {
+                    throw error_already_set();
+                }
+                pybind11_fail("Unable to get capsule context");
+            }
+            const char *name = get_name_in_error_scope(o);
+            void *ptr = PyCapsule_GetPointer(o, name);
+            if (ptr == nullptr) {
+                throw error_already_set();
+            }
+            destructor(ptr);
+        });
+
+        if (!m_ptr || PyCapsule_SetContext(m_ptr, (void *) destructor) != 0) {
+            throw error_already_set();
+        }
+    }
+
+    explicit capsule(void (*destructor)()) {
+        m_ptr = PyCapsule_New(reinterpret_cast<void *>(destructor), nullptr, [](PyObject *o) {
+            const char *name = get_name_in_error_scope(o);
+            auto destructor = reinterpret_cast<void (*)()>(PyCapsule_GetPointer(o, name));
+            if (destructor == nullptr) {
+                throw error_already_set();
+            }
+            destructor();
+        });
+
+        if (!m_ptr) {
+            throw error_already_set();
+        }
+    }
+
+    template <typename T>
+    operator T *() const { // NOLINT(google-explicit-constructor)
+        return get_pointer<T>();
+    }
+
+    /// Get the pointer the capsule holds.
+    template <typename T = void>
+    T *get_pointer() const {
+        const auto *name = this->name();
+        T *result = static_cast<T *>(PyCapsule_GetPointer(m_ptr, name));
+        if (!result) {
+            throw error_already_set();
+        }
+        return result;
+    }
+
+    /// Replaces a capsule's pointer *without* calling the destructor on the existing one.
+    void set_pointer(const void *value) {
+        if (PyCapsule_SetPointer(m_ptr, const_cast<void *>(value)) != 0) {
+            throw error_already_set();
+        }
+    }
+
+    const char *name() const {
+        const char *name = PyCapsule_GetName(m_ptr);
+        if ((name == nullptr) && PyErr_Occurred()) {
+            throw error_already_set();
+        }
+        return name;
+    }
+
+    /// Replaces a capsule's name *without* calling the destructor on the existing one.
+    void set_name(const char *new_name) {
+        if (PyCapsule_SetName(m_ptr, new_name) != 0) {
+            throw error_already_set();
+        }
+    }
+
+private:
+    static const char *get_name_in_error_scope(PyObject *o) {
+        error_scope error_guard;
+
+        const char *name = PyCapsule_GetName(o);
+        if ((name == nullptr) && PyErr_Occurred()) {
+            // write out and consume error raised by call to PyCapsule_GetName
+            PyErr_WriteUnraisable(o);
+        }
+
+        return name;
+    }
+};
+
+class tuple : public object {
+public:
+    PYBIND11_OBJECT_CVT(tuple, object, PyTuple_Check, PySequence_Tuple)
+    template <typename SzType = ssize_t,
+              detail::enable_if_t<std::is_integral<SzType>::value, int> = 0>
+    // Some compilers generate link errors when using `const SzType &` here:
+    explicit tuple(SzType size = 0) : object(PyTuple_New(ssize_t_cast(size)), stolen_t{}) {
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate tuple object!");
+        }
+    }
+    size_t size() const { return (size_t) PyTuple_Size(m_ptr); }
+    bool empty() const { return size() == 0; }
+    detail::tuple_accessor operator[](size_t index) const { return {*this, index}; }
+    template <typename T, detail::enable_if_t<detail::is_pyobject<T>::value, int> = 0>
+    detail::item_accessor operator[](T &&o) const {
+        return object::operator[](std::forward<T>(o));
+    }
+    detail::tuple_iterator begin() const { return {*this, 0}; }
+    detail::tuple_iterator end() const { return {*this, PyTuple_GET_SIZE(m_ptr)}; }
+};
+
+// We need to put this into a separate function because the Intel compiler
+// fails to compile enable_if_t<all_of<is_keyword_or_ds<Args>...>::value> part below
+// (tested with ICC 2021.1 Beta 20200827).
+template <typename... Args>
+constexpr bool args_are_all_keyword_or_ds() {
+    return detail::all_of<detail::is_keyword_or_ds<Args>...>::value;
+}
+
+class dict : public object {
+public:
+    PYBIND11_OBJECT_CVT(dict, object, PyDict_Check, raw_dict)
+    dict() : object(PyDict_New(), stolen_t{}) {
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate dict object!");
+        }
+    }
+    template <typename... Args,
+              typename = detail::enable_if_t<args_are_all_keyword_or_ds<Args...>()>,
+              // MSVC workaround: it can't compile an out-of-line definition, so defer the
+              // collector
+              typename collector = detail::deferred_t<detail::unpacking_collector<>, Args...>>
+    explicit dict(Args &&...args) : dict(collector(std::forward<Args>(args)...).kwargs()) {}
+
+    size_t size() const { return (size_t) PyDict_Size(m_ptr); }
+    bool empty() const { return size() == 0; }
+    detail::dict_iterator begin() const { return {*this, 0}; }
+    detail::dict_iterator end() const { return {}; }
+    void clear() /* py-non-const */ { PyDict_Clear(ptr()); }
+    template <typename T>
+    bool contains(T &&key) const {
+        return PyDict_Contains(m_ptr, detail::object_or_cast(std::forward<T>(key)).ptr()) == 1;
+    }
+
+private:
+    /// Call the `dict` Python type -- always returns a new reference
+    static PyObject *raw_dict(PyObject *op) {
+        if (PyDict_Check(op)) {
+            return handle(op).inc_ref().ptr();
+        }
+        return PyObject_CallFunctionObjArgs((PyObject *) &PyDict_Type, op, nullptr);
+    }
+};
+
+class sequence : public object {
+public:
+    PYBIND11_OBJECT_DEFAULT(sequence, object, PySequence_Check)
+    size_t size() const {
+        ssize_t result = PySequence_Size(m_ptr);
+        if (result == -1) {
+            throw error_already_set();
+        }
+        return (size_t) result;
+    }
+    bool empty() const { return size() == 0; }
+    detail::sequence_accessor operator[](size_t index) const { return {*this, index}; }
+    template <typename T, detail::enable_if_t<detail::is_pyobject<T>::value, int> = 0>
+    detail::item_accessor operator[](T &&o) const {
+        return object::operator[](std::forward<T>(o));
+    }
+    detail::sequence_iterator begin() const { return {*this, 0}; }
+    detail::sequence_iterator end() const { return {*this, PySequence_Size(m_ptr)}; }
+};
+
+class list : public object {
+public:
+    PYBIND11_OBJECT_CVT(list, object, PyList_Check, PySequence_List)
+    template <typename SzType = ssize_t,
+              detail::enable_if_t<std::is_integral<SzType>::value, int> = 0>
+    // Some compilers generate link errors when using `const SzType &` here:
+    explicit list(SzType size = 0) : object(PyList_New(ssize_t_cast(size)), stolen_t{}) {
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate list object!");
+        }
+    }
+    size_t size() const { return (size_t) PyList_Size(m_ptr); }
+    bool empty() const { return size() == 0; }
+    detail::list_accessor operator[](size_t index) const { return {*this, index}; }
+    template <typename T, detail::enable_if_t<detail::is_pyobject<T>::value, int> = 0>
+    detail::item_accessor operator[](T &&o) const {
+        return object::operator[](std::forward<T>(o));
+    }
+    detail::list_iterator begin() const { return {*this, 0}; }
+    detail::list_iterator end() const { return {*this, PyList_GET_SIZE(m_ptr)}; }
+    template <typename T>
+    void append(T &&val) /* py-non-const */ {
+        PyList_Append(m_ptr, detail::object_or_cast(std::forward<T>(val)).ptr());
+    }
+    template <typename IdxType,
+              typename ValType,
+              detail::enable_if_t<std::is_integral<IdxType>::value, int> = 0>
+    void insert(const IdxType &index, ValType &&val) /* py-non-const */ {
+        PyList_Insert(
+            m_ptr, ssize_t_cast(index), detail::object_or_cast(std::forward<ValType>(val)).ptr());
+    }
+};
+
+class args : public tuple {
+    PYBIND11_OBJECT_DEFAULT(args, tuple, PyTuple_Check)
+};
+class kwargs : public dict {
+    PYBIND11_OBJECT_DEFAULT(kwargs, dict, PyDict_Check)
+};
+
+class anyset : public object {
+public:
+    PYBIND11_OBJECT(anyset, object, PyAnySet_Check)
+    size_t size() const { return static_cast<size_t>(PySet_Size(m_ptr)); }
+    bool empty() const { return size() == 0; }
+    template <typename T>
+    bool contains(T &&val) const {
+        return PySet_Contains(m_ptr, detail::object_or_cast(std::forward<T>(val)).ptr()) == 1;
+    }
+};
+
+class set : public anyset {
+public:
+    PYBIND11_OBJECT_CVT(set, anyset, PySet_Check, PySet_New)
+    set() : anyset(PySet_New(nullptr), stolen_t{}) {
+        if (!m_ptr) {
+            pybind11_fail("Could not allocate set object!");
+        }
+    }
+    template <typename T>
+    bool add(T &&val) /* py-non-const */ {
+        return PySet_Add(m_ptr, detail::object_or_cast(std::forward<T>(val)).ptr()) == 0;
+    }
+    void clear() /* py-non-const */ { PySet_Clear(m_ptr); }
+};
+
+class frozenset : public anyset {
+public:
+    PYBIND11_OBJECT_CVT(frozenset, anyset, PyFrozenSet_Check, PyFrozenSet_New)
+};
+
+class function : public object {
+public:
+    PYBIND11_OBJECT_DEFAULT(function, object, PyCallable_Check)
+    handle cpp_function() const {
+        handle fun = detail::get_function(m_ptr);
+        if (fun && PyCFunction_Check(fun.ptr())) {
+            return fun;
+        }
+        return handle();
+    }
+    bool is_cpp_function() const { return (bool) cpp_function(); }
+};
+
+class staticmethod : public object {
+public:
+    PYBIND11_OBJECT_CVT(staticmethod, object, detail::PyStaticMethod_Check, PyStaticMethod_New)
+};
+
+class buffer : public object {
+public:
+    PYBIND11_OBJECT_DEFAULT(buffer, object, PyObject_CheckBuffer)
+
+    buffer_info request(bool writable = false) const {
+        int flags = PyBUF_STRIDES | PyBUF_FORMAT;
+        if (writable) {
+            flags |= PyBUF_WRITABLE;
+        }
+        auto *view = new Py_buffer();
+        if (PyObject_GetBuffer(m_ptr, view, flags) != 0) {
+            delete view;
+            throw error_already_set();
+        }
+        return buffer_info(view);
+    }
+};
+
+class memoryview : public object {
+public:
+    PYBIND11_OBJECT_CVT(memoryview, object, PyMemoryView_Check, PyMemoryView_FromObject)
+
+    /** \rst
+        Creates ``memoryview`` from ``buffer_info``.
+
+        ``buffer_info`` must be created from ``buffer::request()``. Otherwise
+        throws an exception.
+
+        For creating a ``memoryview`` from objects that support buffer protocol,
+        use ``memoryview(const object& obj)`` instead of this constructor.
+     \endrst */
+    explicit memoryview(const buffer_info &info) {
+        if (!info.view()) {
+            pybind11_fail("Prohibited to create memoryview without Py_buffer");
+        }
+        // Note: PyMemoryView_FromBuffer never increments obj reference.
+        m_ptr = (info.view()->obj) ? PyMemoryView_FromObject(info.view()->obj)
+                                   : PyMemoryView_FromBuffer(info.view());
+        if (!m_ptr) {
+            pybind11_fail("Unable to create memoryview from buffer descriptor");
+        }
+    }
+
+    /** \rst
+        Creates ``memoryview`` from static buffer.
+
+        This method is meant for providing a ``memoryview`` for C/C++ buffer not
+        managed by Python. The caller is responsible for managing the lifetime
+        of ``ptr`` and ``format``, which MUST outlive the memoryview constructed
+        here.
+
+        See also: Python C API documentation for `PyMemoryView_FromBuffer`_.
+
+        .. _PyMemoryView_FromBuffer:
+           https://docs.python.org/c-api/memoryview.html#c.PyMemoryView_FromBuffer
+
+        :param ptr: Pointer to the buffer.
+        :param itemsize: Byte size of an element.
+        :param format: Pointer to the null-terminated format string. For
+            homogeneous Buffers, this should be set to
+            ``format_descriptor<T>::value``.
+        :param shape: Shape of the tensor (1 entry per dimension).
+        :param strides: Number of bytes between adjacent entries (for each
+            per dimension).
+        :param readonly: Flag to indicate if the underlying storage may be
+            written to.
+     \endrst */
+    static memoryview from_buffer(void *ptr,
+                                  ssize_t itemsize,
+                                  const char *format,
+                                  detail::any_container<ssize_t> shape,
+                                  detail::any_container<ssize_t> strides,
+                                  bool readonly = false);
+
+    static memoryview from_buffer(const void *ptr,
+                                  ssize_t itemsize,
+                                  const char *format,
+                                  detail::any_container<ssize_t> shape,
+                                  detail::any_container<ssize_t> strides) {
+        return memoryview::from_buffer(
+            const_cast<void *>(ptr), itemsize, format, std::move(shape), std::move(strides), true);
+    }
+
+    template <typename T>
+    static memoryview from_buffer(T *ptr,
+                                  detail::any_container<ssize_t> shape,
+                                  detail::any_container<ssize_t> strides,
+                                  bool readonly = false) {
+        return memoryview::from_buffer(reinterpret_cast<void *>(ptr),
+                                       sizeof(T),
+                                       format_descriptor<T>::value,
+                                       std::move(shape),
+                                       std::move(strides),
+                                       readonly);
+    }
+
+    template <typename T>
+    static memoryview from_buffer(const T *ptr,
+                                  detail::any_container<ssize_t> shape,
+                                  detail::any_container<ssize_t> strides) {
+        return memoryview::from_buffer(
+            const_cast<T *>(ptr), std::move(shape), std::move(strides), true);
+    }
+
+    /** \rst
+        Creates ``memoryview`` from static memory.
+
+        This method is meant for providing a ``memoryview`` for C/C++ buffer not
+        managed by Python. The caller is responsible for managing the lifetime
+        of ``mem``, which MUST outlive the memoryview constructed here.
+
+        See also: Python C API documentation for `PyMemoryView_FromBuffer`_.
+
+        .. _PyMemoryView_FromMemory:
+           https://docs.python.org/c-api/memoryview.html#c.PyMemoryView_FromMemory
+     \endrst */
+    static memoryview from_memory(void *mem, ssize_t size, bool readonly = false) {
+        PyObject *ptr = PyMemoryView_FromMemory(
+            reinterpret_cast<char *>(mem), size, (readonly) ? PyBUF_READ : PyBUF_WRITE);
+        if (!ptr) {
+            pybind11_fail("Could not allocate memoryview object!");
+        }
+        return memoryview(object(ptr, stolen_t{}));
+    }
+
+    static memoryview from_memory(const void *mem, ssize_t size) {
+        return memoryview::from_memory(const_cast<void *>(mem), size, true);
+    }
+
+#ifdef PYBIND11_HAS_STRING_VIEW
+    static memoryview from_memory(std::string_view mem) {
+        return from_memory(const_cast<char *>(mem.data()), static_cast<ssize_t>(mem.size()), true);
+    }
+#endif
+};
+
+/// @cond DUPLICATE
+inline memoryview memoryview::from_buffer(void *ptr,
+                                          ssize_t itemsize,
+                                          const char *format,
+                                          detail::any_container<ssize_t> shape,
+                                          detail::any_container<ssize_t> strides,
+                                          bool readonly) {
+    size_t ndim = shape->size();
+    if (ndim != strides->size()) {
+        pybind11_fail("memoryview: shape length doesn't match strides length");
+    }
+    ssize_t size = ndim != 0u ? 1 : 0;
+    for (size_t i = 0; i < ndim; ++i) {
+        size *= (*shape)[i];
+    }
+    Py_buffer view;
+    view.buf = ptr;
+    view.obj = nullptr;
+    view.len = size * itemsize;
+    view.readonly = static_cast<int>(readonly);
+    view.itemsize = itemsize;
+    view.format = const_cast<char *>(format);
+    view.ndim = static_cast<int>(ndim);
+    view.shape = shape->data();
+    view.strides = strides->data();
+    view.suboffsets = nullptr;
+    view.internal = nullptr;
+    PyObject *obj = PyMemoryView_FromBuffer(&view);
+    if (!obj) {
+        throw error_already_set();
+    }
+    return memoryview(object(obj, stolen_t{}));
+}
+/// @endcond
+/// @} pytypes
+
+/// \addtogroup python_builtins
+/// @{
+
+/// Get the length of a Python object.
+inline size_t len(handle h) {
+    ssize_t result = PyObject_Length(h.ptr());
+    if (result < 0) {
+        throw error_already_set();
+    }
+    return (size_t) result;
+}
+
+/// Get the length hint of a Python object.
+/// Returns 0 when this cannot be determined.
+inline size_t len_hint(handle h) {
+    ssize_t result = PyObject_LengthHint(h.ptr(), 0);
+    if (result < 0) {
+        // Sometimes a length can't be determined at all (eg generators)
+        // In which case simply return 0
+        PyErr_Clear();
+        return 0;
+    }
+    return (size_t) result;
+}
+
+inline str repr(handle h) {
+    PyObject *str_value = PyObject_Repr(h.ptr());
+    if (!str_value) {
+        throw error_already_set();
+    }
+    return reinterpret_steal<str>(str_value);
+}
+
+inline iterator iter(handle obj) {
+    PyObject *result = PyObject_GetIter(obj.ptr());
+    if (!result) {
+        throw error_already_set();
+    }
+    return reinterpret_steal<iterator>(result);
+}
+/// @} python_builtins
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+template <typename D>
+iterator object_api<D>::begin() const {
+    return iter(derived());
+}
+template <typename D>
+iterator object_api<D>::end() const {
+    return iterator::sentinel();
+}
+template <typename D>
+item_accessor object_api<D>::operator[](handle key) const {
+    return {derived(), reinterpret_borrow<object>(key)};
+}
+template <typename D>
+item_accessor object_api<D>::operator[](object &&key) const {
+    return {derived(), std::move(key)};
+}
+template <typename D>
+item_accessor object_api<D>::operator[](const char *key) const {
+    return {derived(), pybind11::str(key)};
+}
+template <typename D>
+obj_attr_accessor object_api<D>::attr(handle key) const {
+    return {derived(), reinterpret_borrow<object>(key)};
+}
+template <typename D>
+obj_attr_accessor object_api<D>::attr(object &&key) const {
+    return {derived(), std::move(key)};
+}
+template <typename D>
+str_attr_accessor object_api<D>::attr(const char *key) const {
+    return {derived(), key};
+}
+template <typename D>
+args_proxy object_api<D>::operator*() const {
+    return args_proxy(derived().ptr());
+}
+template <typename D>
+template <typename T>
+bool object_api<D>::contains(T &&item) const {
+    return attr("__contains__")(std::forward<T>(item)).template cast<bool>();
+}
+
+template <typename D>
+pybind11::str object_api<D>::str() const {
+    return pybind11::str(derived());
+}
+
+template <typename D>
+str_attr_accessor object_api<D>::doc() const {
+    return attr("__doc__");
+}
+
+template <typename D>
+handle object_api<D>::get_type() const {
+    return type::handle_of(derived());
+}
+
+template <typename D>
+bool object_api<D>::rich_compare(object_api const &other, int value) const {
+    int rv = PyObject_RichCompareBool(derived().ptr(), other.derived().ptr(), value);
+    if (rv == -1) {
+        throw error_already_set();
+    }
+    return rv == 1;
+}
+
+#define PYBIND11_MATH_OPERATOR_UNARY(op, fn)                                                      \
+    template <typename D>                                                                         \
+    object object_api<D>::op() const {                                                            \
+        object result = reinterpret_steal<object>(fn(derived().ptr()));                           \
+        if (!result.ptr())                                                                        \
+            throw error_already_set();                                                            \
+        return result;                                                                            \
+    }
+
+#define PYBIND11_MATH_OPERATOR_BINARY(op, fn)                                                     \
+    template <typename D>                                                                         \
+    object object_api<D>::op(object_api const &other) const {                                     \
+        object result = reinterpret_steal<object>(fn(derived().ptr(), other.derived().ptr()));    \
+        if (!result.ptr())                                                                        \
+            throw error_already_set();                                                            \
+        return result;                                                                            \
+    }
+
+PYBIND11_MATH_OPERATOR_UNARY(operator~, PyNumber_Invert)
+PYBIND11_MATH_OPERATOR_UNARY(operator-, PyNumber_Negative)
+PYBIND11_MATH_OPERATOR_BINARY(operator+, PyNumber_Add)
+PYBIND11_MATH_OPERATOR_BINARY(operator+=, PyNumber_InPlaceAdd)
+PYBIND11_MATH_OPERATOR_BINARY(operator-, PyNumber_Subtract)
+PYBIND11_MATH_OPERATOR_BINARY(operator-=, PyNumber_InPlaceSubtract)
+PYBIND11_MATH_OPERATOR_BINARY(operator*, PyNumber_Multiply)
+PYBIND11_MATH_OPERATOR_BINARY(operator*=, PyNumber_InPlaceMultiply)
+PYBIND11_MATH_OPERATOR_BINARY(operator/, PyNumber_TrueDivide)
+PYBIND11_MATH_OPERATOR_BINARY(operator/=, PyNumber_InPlaceTrueDivide)
+PYBIND11_MATH_OPERATOR_BINARY(operator|, PyNumber_Or)
+PYBIND11_MATH_OPERATOR_BINARY(operator|=, PyNumber_InPlaceOr)
+PYBIND11_MATH_OPERATOR_BINARY(operator&, PyNumber_And)
+PYBIND11_MATH_OPERATOR_BINARY(operator&=, PyNumber_InPlaceAnd)
+PYBIND11_MATH_OPERATOR_BINARY(operator^, PyNumber_Xor)
+PYBIND11_MATH_OPERATOR_BINARY(operator^=, PyNumber_InPlaceXor)
+PYBIND11_MATH_OPERATOR_BINARY(operator<<, PyNumber_Lshift)
+PYBIND11_MATH_OPERATOR_BINARY(operator<<=, PyNumber_InPlaceLshift)
+PYBIND11_MATH_OPERATOR_BINARY(operator>>, PyNumber_Rshift)
+PYBIND11_MATH_OPERATOR_BINARY(operator>>=, PyNumber_InPlaceRshift)
+
+#undef PYBIND11_MATH_OPERATOR_UNARY
+#undef PYBIND11_MATH_OPERATOR_BINARY
+
+PYBIND11_NAMESPACE_END(detail)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

third-party/DPVO/DPViewer/pybind11/include/pybind11/stl.h

@@ -0,0 +1,425 @@
+/*
+    pybind11/stl.h: Transparent conversion for STL data types
+
+    Copyright (c) 2016 Wenzel Jakob <[email protected]>
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "pybind11.h"
+#include "detail/common.h"
+
+#include <deque>
+#include <list>
+#include <map>
+#include <ostream>
+#include <set>
+#include <unordered_map>
+#include <unordered_set>
+#include <valarray>
+
+// See `detail/common.h` for implementation of these guards.
+#if defined(PYBIND11_HAS_OPTIONAL)
+#    include <optional>
+#elif defined(PYBIND11_HAS_EXP_OPTIONAL)
+#    include <experimental/optional>
+#endif
+
+#if defined(PYBIND11_HAS_VARIANT)
+#    include <variant>
+#endif
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+/// Extracts an const lvalue reference or rvalue reference for U based on the type of T (e.g. for
+/// forwarding a container element).  Typically used indirect via forwarded_type(), below.
+template <typename T, typename U>
+using forwarded_type = conditional_t<std::is_lvalue_reference<T>::value,
+                                     remove_reference_t<U> &,
+                                     remove_reference_t<U> &&>;
+
+/// Forwards a value U as rvalue or lvalue according to whether T is rvalue or lvalue; typically
+/// used for forwarding a container's elements.
+template <typename T, typename U>
+forwarded_type<T, U> forward_like(U &&u) {
+    return std::forward<detail::forwarded_type<T, U>>(std::forward<U>(u));
+}
+
+template <typename Type, typename Key>
+struct set_caster {
+    using type = Type;
+    using key_conv = make_caster<Key>;
+
+    bool load(handle src, bool convert) {
+        if (!isinstance<anyset>(src)) {
+            return false;
+        }
+        auto s = reinterpret_borrow<anyset>(src);
+        value.clear();
+        for (auto entry : s) {
+            key_conv conv;
+            if (!conv.load(entry, convert)) {
+                return false;
+            }
+            value.insert(cast_op<Key &&>(std::move(conv)));
+        }
+        return true;
+    }
+
+    template <typename T>
+    static handle cast(T &&src, return_value_policy policy, handle parent) {
+        if (!std::is_lvalue_reference<T>::value) {
+            policy = return_value_policy_override<Key>::policy(policy);
+        }
+        pybind11::set s;
+        for (auto &&value : src) {
+            auto value_ = reinterpret_steal<object>(
+                key_conv::cast(forward_like<T>(value), policy, parent));
+            if (!value_ || !s.add(std::move(value_))) {
+                return handle();
+            }
+        }
+        return s.release();
+    }
+
+    PYBIND11_TYPE_CASTER(type, const_name("Set[") + key_conv::name + const_name("]"));
+};
+
+template <typename Type, typename Key, typename Value>
+struct map_caster {
+    using key_conv = make_caster<Key>;
+    using value_conv = make_caster<Value>;
+
+    bool load(handle src, bool convert) {
+        if (!isinstance<dict>(src)) {
+            return false;
+        }
+        auto d = reinterpret_borrow<dict>(src);
+        value.clear();
+        for (auto it : d) {
+            key_conv kconv;
+            value_conv vconv;
+            if (!kconv.load(it.first.ptr(), convert) || !vconv.load(it.second.ptr(), convert)) {
+                return false;
+            }
+            value.emplace(cast_op<Key &&>(std::move(kconv)), cast_op<Value &&>(std::move(vconv)));
+        }
+        return true;
+    }
+
+    template <typename T>
+    static handle cast(T &&src, return_value_policy policy, handle parent) {
+        dict d;
+        return_value_policy policy_key = policy;
+        return_value_policy policy_value = policy;
+        if (!std::is_lvalue_reference<T>::value) {
+            policy_key = return_value_policy_override<Key>::policy(policy_key);
+            policy_value = return_value_policy_override<Value>::policy(policy_value);
+        }
+        for (auto &&kv : src) {
+            auto key = reinterpret_steal<object>(
+                key_conv::cast(forward_like<T>(kv.first), policy_key, parent));
+            auto value = reinterpret_steal<object>(
+                value_conv::cast(forward_like<T>(kv.second), policy_value, parent));
+            if (!key || !value) {
+                return handle();
+            }
+            d[std::move(key)] = std::move(value);
+        }
+        return d.release();
+    }
+
+    PYBIND11_TYPE_CASTER(Type,
+                         const_name("Dict[") + key_conv::name + const_name(", ") + value_conv::name
+                             + const_name("]"));
+};
+
+template <typename Type, typename Value>
+struct list_caster {
+    using value_conv = make_caster<Value>;
+
+    bool load(handle src, bool convert) {
+        if (!isinstance<sequence>(src) || isinstance<bytes>(src) || isinstance<str>(src)) {
+            return false;
+        }
+        auto s = reinterpret_borrow<sequence>(src);
+        value.clear();
+        reserve_maybe(s, &value);
+        for (auto it : s) {
+            value_conv conv;
+            if (!conv.load(it, convert)) {
+                return false;
+            }
+            value.push_back(cast_op<Value &&>(std::move(conv)));
+        }
+        return true;
+    }
+
+private:
+    template <
+        typename T = Type,
+        enable_if_t<std::is_same<decltype(std::declval<T>().reserve(0)), void>::value, int> = 0>
+    void reserve_maybe(const sequence &s, Type *) {
+        value.reserve(s.size());
+    }
+    void reserve_maybe(const sequence &, void *) {}
+
+public:
+    template <typename T>
+    static handle cast(T &&src, return_value_policy policy, handle parent) {
+        if (!std::is_lvalue_reference<T>::value) {
+            policy = return_value_policy_override<Value>::policy(policy);
+        }
+        list l(src.size());
+        ssize_t index = 0;
+        for (auto &&value : src) {
+            auto value_ = reinterpret_steal<object>(
+                value_conv::cast(forward_like<T>(value), policy, parent));
+            if (!value_) {
+                return handle();
+            }
+            PyList_SET_ITEM(l.ptr(), index++, value_.release().ptr()); // steals a reference
+        }
+        return l.release();
+    }
+
+    PYBIND11_TYPE_CASTER(Type, const_name("List[") + value_conv::name + const_name("]"));
+};
+
+template <typename Type, typename Alloc>
+struct type_caster<std::vector<Type, Alloc>> : list_caster<std::vector<Type, Alloc>, Type> {};
+
+template <typename Type, typename Alloc>
+struct type_caster<std::deque<Type, Alloc>> : list_caster<std::deque<Type, Alloc>, Type> {};
+
+template <typename Type, typename Alloc>
+struct type_caster<std::list<Type, Alloc>> : list_caster<std::list<Type, Alloc>, Type> {};
+
+template <typename ArrayType, typename Value, bool Resizable, size_t Size = 0>
+struct array_caster {
+    using value_conv = make_caster<Value>;
+
+private:
+    template <bool R = Resizable>
+    bool require_size(enable_if_t<R, size_t> size) {
+        if (value.size() != size) {
+            value.resize(size);
+        }
+        return true;
+    }
+    template <bool R = Resizable>
+    bool require_size(enable_if_t<!R, size_t> size) {
+        return size == Size;
+    }
+
+public:
+    bool load(handle src, bool convert) {
+        if (!isinstance<sequence>(src)) {
+            return false;
+        }
+        auto l = reinterpret_borrow<sequence>(src);
+        if (!require_size(l.size())) {
+            return false;
+        }
+        size_t ctr = 0;
+        for (auto it : l) {
+            value_conv conv;
+            if (!conv.load(it, convert)) {
+                return false;
+            }
+            value[ctr++] = cast_op<Value &&>(std::move(conv));
+        }
+        return true;
+    }
+
+    template <typename T>
+    static handle cast(T &&src, return_value_policy policy, handle parent) {
+        list l(src.size());
+        ssize_t index = 0;
+        for (auto &&value : src) {
+            auto value_ = reinterpret_steal<object>(
+                value_conv::cast(forward_like<T>(value), policy, parent));
+            if (!value_) {
+                return handle();
+            }
+            PyList_SET_ITEM(l.ptr(), index++, value_.release().ptr()); // steals a reference
+        }
+        return l.release();
+    }
+
+    PYBIND11_TYPE_CASTER(ArrayType,
+                         const_name("List[") + value_conv::name
+                             + const_name<Resizable>(const_name(""),
+                                                     const_name("[") + const_name<Size>()
+                                                         + const_name("]"))
+                             + const_name("]"));
+};
+
+template <typename Type, size_t Size>
+struct type_caster<std::array<Type, Size>>
+    : array_caster<std::array<Type, Size>, Type, false, Size> {};
+
+template <typename Type>
+struct type_caster<std::valarray<Type>> : array_caster<std::valarray<Type>, Type, true> {};
+
+template <typename Key, typename Compare, typename Alloc>
+struct type_caster<std::set<Key, Compare, Alloc>>
+    : set_caster<std::set<Key, Compare, Alloc>, Key> {};
+
+template <typename Key, typename Hash, typename Equal, typename Alloc>
+struct type_caster<std::unordered_set<Key, Hash, Equal, Alloc>>
+    : set_caster<std::unordered_set<Key, Hash, Equal, Alloc>, Key> {};
+
+template <typename Key, typename Value, typename Compare, typename Alloc>
+struct type_caster<std::map<Key, Value, Compare, Alloc>>
+    : map_caster<std::map<Key, Value, Compare, Alloc>, Key, Value> {};
+
+template <typename Key, typename Value, typename Hash, typename Equal, typename Alloc>
+struct type_caster<std::unordered_map<Key, Value, Hash, Equal, Alloc>>
+    : map_caster<std::unordered_map<Key, Value, Hash, Equal, Alloc>, Key, Value> {};
+
+// This type caster is intended to be used for std::optional and std::experimental::optional
+template <typename Type, typename Value = typename Type::value_type>
+struct optional_caster {
+    using value_conv = make_caster<Value>;
+
+    template <typename T>
+    static handle cast(T &&src, return_value_policy policy, handle parent) {
+        if (!src) {
+            return none().inc_ref();
+        }
+        if (!std::is_lvalue_reference<T>::value) {
+            policy = return_value_policy_override<Value>::policy(policy);
+        }
+        return value_conv::cast(*std::forward<T>(src), policy, parent);
+    }
+
+    bool load(handle src, bool convert) {
+        if (!src) {
+            return false;
+        }
+        if (src.is_none()) {
+            return true; // default-constructed value is already empty
+        }
+        value_conv inner_caster;
+        if (!inner_caster.load(src, convert)) {
+            return false;
+        }
+
+        value.emplace(cast_op<Value &&>(std::move(inner_caster)));
+        return true;
+    }
+
+    PYBIND11_TYPE_CASTER(Type, const_name("Optional[") + value_conv::name + const_name("]"));
+};
+
+#if defined(PYBIND11_HAS_OPTIONAL)
+template <typename T>
+struct type_caster<std::optional<T>> : public optional_caster<std::optional<T>> {};
+
+template <>
+struct type_caster<std::nullopt_t> : public void_caster<std::nullopt_t> {};
+#endif
+
+#if defined(PYBIND11_HAS_EXP_OPTIONAL)
+template <typename T>
+struct type_caster<std::experimental::optional<T>>
+    : public optional_caster<std::experimental::optional<T>> {};
+
+template <>
+struct type_caster<std::experimental::nullopt_t>
+    : public void_caster<std::experimental::nullopt_t> {};
+#endif
+
+/// Visit a variant and cast any found type to Python
+struct variant_caster_visitor {
+    return_value_policy policy;
+    handle parent;
+
+    using result_type = handle; // required by boost::variant in C++11
+
+    template <typename T>
+    result_type operator()(T &&src) const {
+        return make_caster<T>::cast(std::forward<T>(src), policy, parent);
+    }
+};
+
+/// Helper class which abstracts away variant's `visit` function. `std::variant` and similar
+/// `namespace::variant` types which provide a `namespace::visit()` function are handled here
+/// automatically using argument-dependent lookup. Users can provide specializations for other
+/// variant-like classes, e.g. `boost::variant` and `boost::apply_visitor`.
+template <template <typename...> class Variant>
+struct visit_helper {
+    template <typename... Args>
+    static auto call(Args &&...args) -> decltype(visit(std::forward<Args>(args)...)) {
+        return visit(std::forward<Args>(args)...);
+    }
+};
+
+/// Generic variant caster
+template <typename Variant>
+struct variant_caster;
+
+template <template <typename...> class V, typename... Ts>
+struct variant_caster<V<Ts...>> {
+    static_assert(sizeof...(Ts) > 0, "Variant must consist of at least one alternative.");
+
+    template <typename U, typename... Us>
+    bool load_alternative(handle src, bool convert, type_list<U, Us...>) {
+        auto caster = make_caster<U>();
+        if (caster.load(src, convert)) {
+            value = cast_op<U>(std::move(caster));
+            return true;
+        }
+        return load_alternative(src, convert, type_list<Us...>{});
+    }
+
+    bool load_alternative(handle, bool, type_list<>) { return false; }
+
+    bool load(handle src, bool convert) {
+        // Do a first pass without conversions to improve constructor resolution.
+        // E.g. `py::int_(1).cast<variant<double, int>>()` needs to fill the `int`
+        // slot of the variant. Without two-pass loading `double` would be filled
+        // because it appears first and a conversion is possible.
+        if (convert && load_alternative(src, false, type_list<Ts...>{})) {
+            return true;
+        }
+        return load_alternative(src, convert, type_list<Ts...>{});
+    }
+
+    template <typename Variant>
+    static handle cast(Variant &&src, return_value_policy policy, handle parent) {
+        return visit_helper<V>::call(variant_caster_visitor{policy, parent},
+                                     std::forward<Variant>(src));
+    }
+
+    using Type = V<Ts...>;
+    PYBIND11_TYPE_CASTER(Type,
+                         const_name("Union[") + detail::concat(make_caster<Ts>::name...)
+                             + const_name("]"));
+};
+
+#if defined(PYBIND11_HAS_VARIANT)
+template <typename... Ts>
+struct type_caster<std::variant<Ts...>> : variant_caster<std::variant<Ts...>> {};
+
+template <>
+struct type_caster<std::monostate> : public void_caster<std::monostate> {};
+#endif
+
+PYBIND11_NAMESPACE_END(detail)
+
+inline std::ostream &operator<<(std::ostream &os, const handle &obj) {
+#ifdef PYBIND11_HAS_STRING_VIEW
+    os << str(obj).cast<std::string_view>();
+#else
+    os << (std::string) str(obj);
+#endif
+    return os;
+}
+
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

third-party/DPVO/DPViewer/pybind11/include/pybind11/stl/filesystem.h

@@ -0,0 +1,116 @@
+// Copyright (c) 2021 The Pybind Development Team.
+// All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#pragma once
+
+#include "../pybind11.h"
+#include "../detail/common.h"
+#include "../detail/descr.h"
+#include "../cast.h"
+#include "../pytypes.h"
+
+#include <string>
+
+#ifdef __has_include
+#    if defined(PYBIND11_CPP17)
+#        if __has_include(<filesystem>) && \
+          PY_VERSION_HEX >= 0x03060000
+#            include <filesystem>
+#            define PYBIND11_HAS_FILESYSTEM 1
+#        elif __has_include(<experimental/filesystem>)
+#            include <experimental/filesystem>
+#            define PYBIND11_HAS_EXPERIMENTAL_FILESYSTEM 1
+#        endif
+#    endif
+#endif
+
+#if !defined(PYBIND11_HAS_FILESYSTEM) && !defined(PYBIND11_HAS_EXPERIMENTAL_FILESYSTEM)           \
+    && !defined(PYBIND11_HAS_FILESYSTEM_IS_OPTIONAL)
+#    error                                                                                        \
+        "Neither #include <filesystem> nor #include <experimental/filesystem is available. (Use -DPYBIND11_HAS_FILESYSTEM_IS_OPTIONAL to ignore.)"
+#endif
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+#if defined(PYBIND11_HAS_FILESYSTEM) || defined(PYBIND11_HAS_EXPERIMENTAL_FILESYSTEM)
+template <typename T>
+struct path_caster {
+
+private:
+    static PyObject *unicode_from_fs_native(const std::string &w) {
+#    if !defined(PYPY_VERSION)
+        return PyUnicode_DecodeFSDefaultAndSize(w.c_str(), ssize_t(w.size()));
+#    else
+        // PyPy mistakenly declares the first parameter as non-const.
+        return PyUnicode_DecodeFSDefaultAndSize(const_cast<char *>(w.c_str()), ssize_t(w.size()));
+#    endif
+    }
+
+    static PyObject *unicode_from_fs_native(const std::wstring &w) {
+        return PyUnicode_FromWideChar(w.c_str(), ssize_t(w.size()));
+    }
+
+public:
+    static handle cast(const T &path, return_value_policy, handle) {
+        if (auto py_str = unicode_from_fs_native(path.native())) {
+            return module_::import("pathlib")
+                .attr("Path")(reinterpret_steal<object>(py_str))
+                .release();
+        }
+        return nullptr;
+    }
+
+    bool load(handle handle, bool) {
+        // PyUnicode_FSConverter and PyUnicode_FSDecoder normally take care of
+        // calling PyOS_FSPath themselves, but that's broken on PyPy (PyPy
+        // issue #3168) so we do it ourselves instead.
+        PyObject *buf = PyOS_FSPath(handle.ptr());
+        if (!buf) {
+            PyErr_Clear();
+            return false;
+        }
+        PyObject *native = nullptr;
+        if constexpr (std::is_same_v<typename T::value_type, char>) {
+            if (PyUnicode_FSConverter(buf, &native) != 0) {
+                if (auto *c_str = PyBytes_AsString(native)) {
+                    // AsString returns a pointer to the internal buffer, which
+                    // must not be free'd.
+                    value = c_str;
+                }
+            }
+        } else if constexpr (std::is_same_v<typename T::value_type, wchar_t>) {
+            if (PyUnicode_FSDecoder(buf, &native) != 0) {
+                if (auto *c_str = PyUnicode_AsWideCharString(native, nullptr)) {
+                    // AsWideCharString returns a new string that must be free'd.
+                    value = c_str; // Copies the string.
+                    PyMem_Free(c_str);
+                }
+            }
+        }
+        Py_XDECREF(native);
+        Py_DECREF(buf);
+        if (PyErr_Occurred()) {
+            PyErr_Clear();
+            return false;
+        }
+        return true;
+    }
+
+    PYBIND11_TYPE_CASTER(T, const_name("os.PathLike"));
+};
+
+#endif // PYBIND11_HAS_FILESYSTEM || defined(PYBIND11_HAS_EXPERIMENTAL_FILESYSTEM)
+
+#if defined(PYBIND11_HAS_FILESYSTEM)
+template <>
+struct type_caster<std::filesystem::path> : public path_caster<std::filesystem::path> {};
+#elif defined(PYBIND11_HAS_EXPERIMENTAL_FILESYSTEM)
+template <>
+struct type_caster<std::experimental::filesystem::path>
+    : public path_caster<std::experimental::filesystem::path> {};
+#endif
+
+PYBIND11_NAMESPACE_END(detail)
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

third-party/DPVO/DPViewer/pybind11/include/pybind11/stl_bind.h

@@ -0,0 +1,785 @@
+/*
+    pybind11/std_bind.h: Binding generators for STL data types
+
+    Copyright (c) 2016 Sergey Lyskov and Wenzel Jakob
+
+    All rights reserved. Use of this source code is governed by a
+    BSD-style license that can be found in the LICENSE file.
+*/
+
+#pragma once
+
+#include "detail/common.h"
+#include "operators.h"
+
+#include <algorithm>
+#include <sstream>
+
+PYBIND11_NAMESPACE_BEGIN(PYBIND11_NAMESPACE)
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+/* SFINAE helper class used by 'is_comparable */
+template <typename T>
+struct container_traits {
+    template <typename T2>
+    static std::true_type
+    test_comparable(decltype(std::declval<const T2 &>() == std::declval<const T2 &>()) *);
+    template <typename T2>
+    static std::false_type test_comparable(...);
+    template <typename T2>
+    static std::true_type test_value(typename T2::value_type *);
+    template <typename T2>
+    static std::false_type test_value(...);
+    template <typename T2>
+    static std::true_type test_pair(typename T2::first_type *, typename T2::second_type *);
+    template <typename T2>
+    static std::false_type test_pair(...);
+
+    static constexpr const bool is_comparable
+        = std::is_same<std::true_type, decltype(test_comparable<T>(nullptr))>::value;
+    static constexpr const bool is_pair
+        = std::is_same<std::true_type, decltype(test_pair<T>(nullptr, nullptr))>::value;
+    static constexpr const bool is_vector
+        = std::is_same<std::true_type, decltype(test_value<T>(nullptr))>::value;
+    static constexpr const bool is_element = !is_pair && !is_vector;
+};
+
+/* Default: is_comparable -> std::false_type */
+template <typename T, typename SFINAE = void>
+struct is_comparable : std::false_type {};
+
+/* For non-map data structures, check whether operator== can be instantiated */
+template <typename T>
+struct is_comparable<
+    T,
+    enable_if_t<container_traits<T>::is_element && container_traits<T>::is_comparable>>
+    : std::true_type {};
+
+/* For a vector/map data structure, recursively check the value type
+   (which is std::pair for maps) */
+template <typename T>
+struct is_comparable<T, enable_if_t<container_traits<T>::is_vector>> {
+    static constexpr const bool value = is_comparable<typename T::value_type>::value;
+};
+
+/* For pairs, recursively check the two data types */
+template <typename T>
+struct is_comparable<T, enable_if_t<container_traits<T>::is_pair>> {
+    static constexpr const bool value = is_comparable<typename T::first_type>::value
+                                        && is_comparable<typename T::second_type>::value;
+};
+
+/* Fallback functions */
+template <typename, typename, typename... Args>
+void vector_if_copy_constructible(const Args &...) {}
+template <typename, typename, typename... Args>
+void vector_if_equal_operator(const Args &...) {}
+template <typename, typename, typename... Args>
+void vector_if_insertion_operator(const Args &...) {}
+template <typename, typename, typename... Args>
+void vector_modifiers(const Args &...) {}
+
+template <typename Vector, typename Class_>
+void vector_if_copy_constructible(enable_if_t<is_copy_constructible<Vector>::value, Class_> &cl) {
+    cl.def(init<const Vector &>(), "Copy constructor");
+}
+
+template <typename Vector, typename Class_>
+void vector_if_equal_operator(enable_if_t<is_comparable<Vector>::value, Class_> &cl) {
+    using T = typename Vector::value_type;
+
+    cl.def(self == self);
+    cl.def(self != self);
+
+    cl.def(
+        "count",
+        [](const Vector &v, const T &x) { return std::count(v.begin(), v.end(), x); },
+        arg("x"),
+        "Return the number of times ``x`` appears in the list");
+
+    cl.def(
+        "remove",
+        [](Vector &v, const T &x) {
+            auto p = std::find(v.begin(), v.end(), x);
+            if (p != v.end()) {
+                v.erase(p);
+            } else {
+                throw value_error();
+            }
+        },
+        arg("x"),
+        "Remove the first item from the list whose value is x. "
+        "It is an error if there is no such item.");
+
+    cl.def(
+        "__contains__",
+        [](const Vector &v, const T &x) { return std::find(v.begin(), v.end(), x) != v.end(); },
+        arg("x"),
+        "Return true the container contains ``x``");
+}
+
+// Vector modifiers -- requires a copyable vector_type:
+// (Technically, some of these (pop and __delitem__) don't actually require copyability, but it
+// seems silly to allow deletion but not insertion, so include them here too.)
+template <typename Vector, typename Class_>
+void vector_modifiers(
+    enable_if_t<is_copy_constructible<typename Vector::value_type>::value, Class_> &cl) {
+    using T = typename Vector::value_type;
+    using SizeType = typename Vector::size_type;
+    using DiffType = typename Vector::difference_type;
+
+    auto wrap_i = [](DiffType i, SizeType n) {
+        if (i < 0) {
+            i += n;
+        }
+        if (i < 0 || (SizeType) i >= n) {
+            throw index_error();
+        }
+        return i;
+    };
+
+    cl.def(
+        "append",
+        [](Vector &v, const T &value) { v.push_back(value); },
+        arg("x"),
+        "Add an item to the end of the list");
+
+    cl.def(init([](const iterable &it) {
+        auto v = std::unique_ptr<Vector>(new Vector());
+        v->reserve(len_hint(it));
+        for (handle h : it) {
+            v->push_back(h.cast<T>());
+        }
+        return v.release();
+    }));
+
+    cl.def(
+        "clear", [](Vector &v) { v.clear(); }, "Clear the contents");
+
+    cl.def(
+        "extend",
+        [](Vector &v, const Vector &src) { v.insert(v.end(), src.begin(), src.end()); },
+        arg("L"),
+        "Extend the list by appending all the items in the given list");
+
+    cl.def(
+        "extend",
+        [](Vector &v, const iterable &it) {
+            const size_t old_size = v.size();
+            v.reserve(old_size + len_hint(it));
+            try {
+                for (handle h : it) {
+                    v.push_back(h.cast<T>());
+                }
+            } catch (const cast_error &) {
+                v.erase(v.begin() + static_cast<typename Vector::difference_type>(old_size),
+                        v.end());
+                try {
+                    v.shrink_to_fit();
+                } catch (const std::exception &) {
+                    // Do nothing
+                }
+                throw;
+            }
+        },
+        arg("L"),
+        "Extend the list by appending all the items in the given list");
+
+    cl.def(
+        "insert",
+        [](Vector &v, DiffType i, const T &x) {
+            // Can't use wrap_i; i == v.size() is OK
+            if (i < 0) {
+                i += v.size();
+            }
+            if (i < 0 || (SizeType) i > v.size()) {
+                throw index_error();
+            }
+            v.insert(v.begin() + i, x);
+        },
+        arg("i"),
+        arg("x"),
+        "Insert an item at a given position.");
+
+    cl.def(
+        "pop",
+        [](Vector &v) {
+            if (v.empty()) {
+                throw index_error();
+            }
+            T t = std::move(v.back());
+            v.pop_back();
+            return t;
+        },
+        "Remove and return the last item");
+
+    cl.def(
+        "pop",
+        [wrap_i](Vector &v, DiffType i) {
+            i = wrap_i(i, v.size());
+            T t = std::move(v[(SizeType) i]);
+            v.erase(std::next(v.begin(), i));
+            return t;
+        },
+        arg("i"),
+        "Remove and return the item at index ``i``");
+
+    cl.def("__setitem__", [wrap_i](Vector &v, DiffType i, const T &t) {
+        i = wrap_i(i, v.size());
+        v[(SizeType) i] = t;
+    });
+
+    /// Slicing protocol
+    cl.def(
+        "__getitem__",
+        [](const Vector &v, const slice &slice) -> Vector * {
+            size_t start = 0, stop = 0, step = 0, slicelength = 0;
+
+            if (!slice.compute(v.size(), &start, &stop, &step, &slicelength)) {
+                throw error_already_set();
+            }
+
+            auto *seq = new Vector();
+            seq->reserve((size_t) slicelength);
+
+            for (size_t i = 0; i < slicelength; ++i) {
+                seq->push_back(v[start]);
+                start += step;
+            }
+            return seq;
+        },
+        arg("s"),
+        "Retrieve list elements using a slice object");
+
+    cl.def(
+        "__setitem__",
+        [](Vector &v, const slice &slice, const Vector &value) {
+            size_t start = 0, stop = 0, step = 0, slicelength = 0;
+            if (!slice.compute(v.size(), &start, &stop, &step, &slicelength)) {
+                throw error_already_set();
+            }
+
+            if (slicelength != value.size()) {
+                throw std::runtime_error(
+                    "Left and right hand size of slice assignment have different sizes!");
+            }
+
+            for (size_t i = 0; i < slicelength; ++i) {
+                v[start] = value[i];
+                start += step;
+            }
+        },
+        "Assign list elements using a slice object");
+
+    cl.def(
+        "__delitem__",
+        [wrap_i](Vector &v, DiffType i) {
+            i = wrap_i(i, v.size());
+            v.erase(v.begin() + i);
+        },
+        "Delete the list elements at index ``i``");
+
+    cl.def(
+        "__delitem__",
+        [](Vector &v, const slice &slice) {
+            size_t start = 0, stop = 0, step = 0, slicelength = 0;
+
+            if (!slice.compute(v.size(), &start, &stop, &step, &slicelength)) {
+                throw error_already_set();
+            }
+
+            if (step == 1 && false) {
+                v.erase(v.begin() + (DiffType) start, v.begin() + DiffType(start + slicelength));
+            } else {
+                for (size_t i = 0; i < slicelength; ++i) {
+                    v.erase(v.begin() + DiffType(start));
+                    start += step - 1;
+                }
+            }
+        },
+        "Delete list elements using a slice object");
+}
+
+// If the type has an operator[] that doesn't return a reference (most notably std::vector<bool>),
+// we have to access by copying; otherwise we return by reference.
+template <typename Vector>
+using vector_needs_copy
+    = negation<std::is_same<decltype(std::declval<Vector>()[typename Vector::size_type()]),
+                            typename Vector::value_type &>>;
+
+// The usual case: access and iterate by reference
+template <typename Vector, typename Class_>
+void vector_accessor(enable_if_t<!vector_needs_copy<Vector>::value, Class_> &cl) {
+    using T = typename Vector::value_type;
+    using SizeType = typename Vector::size_type;
+    using DiffType = typename Vector::difference_type;
+    using ItType = typename Vector::iterator;
+
+    auto wrap_i = [](DiffType i, SizeType n) {
+        if (i < 0) {
+            i += n;
+        }
+        if (i < 0 || (SizeType) i >= n) {
+            throw index_error();
+        }
+        return i;
+    };
+
+    cl.def(
+        "__getitem__",
+        [wrap_i](Vector &v, DiffType i) -> T & {
+            i = wrap_i(i, v.size());
+            return v[(SizeType) i];
+        },
+        return_value_policy::reference_internal // ref + keepalive
+    );
+
+    cl.def(
+        "__iter__",
+        [](Vector &v) {
+            return make_iterator<return_value_policy::reference_internal, ItType, ItType, T &>(
+                v.begin(), v.end());
+        },
+        keep_alive<0, 1>() /* Essential: keep list alive while iterator exists */
+    );
+}
+
+// The case for special objects, like std::vector<bool>, that have to be returned-by-copy:
+template <typename Vector, typename Class_>
+void vector_accessor(enable_if_t<vector_needs_copy<Vector>::value, Class_> &cl) {
+    using T = typename Vector::value_type;
+    using SizeType = typename Vector::size_type;
+    using DiffType = typename Vector::difference_type;
+    using ItType = typename Vector::iterator;
+    cl.def("__getitem__", [](const Vector &v, DiffType i) -> T {
+        if (i < 0 && (i += v.size()) < 0) {
+            throw index_error();
+        }
+        if ((SizeType) i >= v.size()) {
+            throw index_error();
+        }
+        return v[(SizeType) i];
+    });
+
+    cl.def(
+        "__iter__",
+        [](Vector &v) {
+            return make_iterator<return_value_policy::copy, ItType, ItType, T>(v.begin(), v.end());
+        },
+        keep_alive<0, 1>() /* Essential: keep list alive while iterator exists */
+    );
+}
+
+template <typename Vector, typename Class_>
+auto vector_if_insertion_operator(Class_ &cl, std::string const &name)
+    -> decltype(std::declval<std::ostream &>() << std::declval<typename Vector::value_type>(),
+                void()) {
+    using size_type = typename Vector::size_type;
+
+    cl.def(
+        "__repr__",
+        [name](Vector &v) {
+            std::ostringstream s;
+            s << name << '[';
+            for (size_type i = 0; i < v.size(); ++i) {
+                s << v[i];
+                if (i != v.size() - 1) {
+                    s << ", ";
+                }
+            }
+            s << ']';
+            return s.str();
+        },
+        "Return the canonical string representation of this list.");
+}
+
+// Provide the buffer interface for vectors if we have data() and we have a format for it
+// GCC seems to have "void std::vector<bool>::data()" - doing SFINAE on the existence of data()
+// is insufficient, we need to check it returns an appropriate pointer
+template <typename Vector, typename = void>
+struct vector_has_data_and_format : std::false_type {};
+template <typename Vector>
+struct vector_has_data_and_format<
+    Vector,
+    enable_if_t<std::is_same<decltype(format_descriptor<typename Vector::value_type>::format(),
+                                      std::declval<Vector>().data()),
+                             typename Vector::value_type *>::value>> : std::true_type {};
+
+// [workaround(intel)] Separate function required here
+// Workaround as the Intel compiler does not compile the enable_if_t part below
+// (tested with icc (ICC) 2021.1 Beta 20200827)
+template <typename... Args>
+constexpr bool args_any_are_buffer() {
+    return detail::any_of<std::is_same<Args, buffer_protocol>...>::value;
+}
+
+// [workaround(intel)] Separate function required here
+// [workaround(msvc)] Can't use constexpr bool in return type
+
+// Add the buffer interface to a vector
+template <typename Vector, typename Class_, typename... Args>
+void vector_buffer_impl(Class_ &cl, std::true_type) {
+    using T = typename Vector::value_type;
+
+    static_assert(vector_has_data_and_format<Vector>::value,
+                  "There is not an appropriate format descriptor for this vector");
+
+    // numpy.h declares this for arbitrary types, but it may raise an exception and crash hard
+    // at runtime if PYBIND11_NUMPY_DTYPE hasn't been called, so check here
+    format_descriptor<T>::format();
+
+    cl.def_buffer([](Vector &v) -> buffer_info {
+        return buffer_info(v.data(),
+                           static_cast<ssize_t>(sizeof(T)),
+                           format_descriptor<T>::format(),
+                           1,
+                           {v.size()},
+                           {sizeof(T)});
+    });
+
+    cl.def(init([](const buffer &buf) {
+        auto info = buf.request();
+        if (info.ndim != 1 || info.strides[0] % static_cast<ssize_t>(sizeof(T))) {
+            throw type_error("Only valid 1D buffers can be copied to a vector");
+        }
+        if (!detail::compare_buffer_info<T>::compare(info)
+            || (ssize_t) sizeof(T) != info.itemsize) {
+            throw type_error("Format mismatch (Python: " + info.format
+                             + " C++: " + format_descriptor<T>::format() + ")");
+        }
+
+        T *p = static_cast<T *>(info.ptr);
+        ssize_t step = info.strides[0] / static_cast<ssize_t>(sizeof(T));
+        T *end = p + info.shape[0] * step;
+        if (step == 1) {
+            return Vector(p, end);
+        }
+        Vector vec;
+        vec.reserve((size_t) info.shape[0]);
+        for (; p != end; p += step) {
+            vec.push_back(*p);
+        }
+        return vec;
+    }));
+
+    return;
+}
+
+template <typename Vector, typename Class_, typename... Args>
+void vector_buffer_impl(Class_ &, std::false_type) {}
+
+template <typename Vector, typename Class_, typename... Args>
+void vector_buffer(Class_ &cl) {
+    vector_buffer_impl<Vector, Class_, Args...>(
+        cl, detail::any_of<std::is_same<Args, buffer_protocol>...>{});
+}
+
+PYBIND11_NAMESPACE_END(detail)
+
+//
+// std::vector
+//
+template <typename Vector, typename holder_type = std::unique_ptr<Vector>, typename... Args>
+class_<Vector, holder_type> bind_vector(handle scope, std::string const &name, Args &&...args) {
+    using Class_ = class_<Vector, holder_type>;
+
+    // If the value_type is unregistered (e.g. a converting type) or is itself registered
+    // module-local then make the vector binding module-local as well:
+    using vtype = typename Vector::value_type;
+    auto *vtype_info = detail::get_type_info(typeid(vtype));
+    bool local = !vtype_info || vtype_info->module_local;
+
+    Class_ cl(scope, name.c_str(), pybind11::module_local(local), std::forward<Args>(args)...);
+
+    // Declare the buffer interface if a buffer_protocol() is passed in
+    detail::vector_buffer<Vector, Class_, Args...>(cl);
+
+    cl.def(init<>());
+
+    // Register copy constructor (if possible)
+    detail::vector_if_copy_constructible<Vector, Class_>(cl);
+
+    // Register comparison-related operators and functions (if possible)
+    detail::vector_if_equal_operator<Vector, Class_>(cl);
+
+    // Register stream insertion operator (if possible)
+    detail::vector_if_insertion_operator<Vector, Class_>(cl, name);
+
+    // Modifiers require copyable vector value type
+    detail::vector_modifiers<Vector, Class_>(cl);
+
+    // Accessor and iterator; return by value if copyable, otherwise we return by ref + keep-alive
+    detail::vector_accessor<Vector, Class_>(cl);
+
+    cl.def(
+        "__bool__",
+        [](const Vector &v) -> bool { return !v.empty(); },
+        "Check whether the list is nonempty");
+
+    cl.def("__len__", &Vector::size);
+
+#if 0
+    // C++ style functions deprecated, leaving it here as an example
+    cl.def(init<size_type>());
+
+    cl.def("resize",
+         (void (Vector::*) (size_type count)) & Vector::resize,
+         "changes the number of elements stored");
+
+    cl.def("erase",
+        [](Vector &v, SizeType i) {
+        if (i >= v.size())
+            throw index_error();
+        v.erase(v.begin() + i);
+    }, "erases element at index ``i``");
+
+    cl.def("empty",         &Vector::empty,         "checks whether the container is empty");
+    cl.def("size",          &Vector::size,          "returns the number of elements");
+    cl.def("push_back", (void (Vector::*)(const T&)) &Vector::push_back, "adds an element to the end");
+    cl.def("pop_back",                               &Vector::pop_back, "removes the last element");
+
+    cl.def("max_size",      &Vector::max_size,      "returns the maximum possible number of elements");
+    cl.def("reserve",       &Vector::reserve,       "reserves storage");
+    cl.def("capacity",      &Vector::capacity,      "returns the number of elements that can be held in currently allocated storage");
+    cl.def("shrink_to_fit", &Vector::shrink_to_fit, "reduces memory usage by freeing unused memory");
+
+    cl.def("clear", &Vector::clear, "clears the contents");
+    cl.def("swap",   &Vector::swap, "swaps the contents");
+
+    cl.def("front", [](Vector &v) {
+        if (v.size()) return v.front();
+        else throw index_error();
+    }, "access the first element");
+
+    cl.def("back", [](Vector &v) {
+        if (v.size()) return v.back();
+        else throw index_error();
+    }, "access the last element ");
+
+#endif
+
+    return cl;
+}
+
+//
+// std::map, std::unordered_map
+//
+
+PYBIND11_NAMESPACE_BEGIN(detail)
+
+/* Fallback functions */
+template <typename, typename, typename... Args>
+void map_if_insertion_operator(const Args &...) {}
+template <typename, typename, typename... Args>
+void map_assignment(const Args &...) {}
+
+// Map assignment when copy-assignable: just copy the value
+template <typename Map, typename Class_>
+void map_assignment(
+    enable_if_t<is_copy_assignable<typename Map::mapped_type>::value, Class_> &cl) {
+    using KeyType = typename Map::key_type;
+    using MappedType = typename Map::mapped_type;
+
+    cl.def("__setitem__", [](Map &m, const KeyType &k, const MappedType &v) {
+        auto it = m.find(k);
+        if (it != m.end()) {
+            it->second = v;
+        } else {
+            m.emplace(k, v);
+        }
+    });
+}
+
+// Not copy-assignable, but still copy-constructible: we can update the value by erasing and
+// reinserting
+template <typename Map, typename Class_>
+void map_assignment(enable_if_t<!is_copy_assignable<typename Map::mapped_type>::value
+                                    && is_copy_constructible<typename Map::mapped_type>::value,
+                                Class_> &cl) {
+    using KeyType = typename Map::key_type;
+    using MappedType = typename Map::mapped_type;
+
+    cl.def("__setitem__", [](Map &m, const KeyType &k, const MappedType &v) {
+        // We can't use m[k] = v; because value type might not be default constructable
+        auto r = m.emplace(k, v);
+        if (!r.second) {
+            // value type is not copy assignable so the only way to insert it is to erase it
+            // first...
+            m.erase(r.first);
+            m.emplace(k, v);
+        }
+    });
+}
+
+template <typename Map, typename Class_>
+auto map_if_insertion_operator(Class_ &cl, std::string const &name)
+    -> decltype(std::declval<std::ostream &>() << std::declval<typename Map::key_type>()
+                                               << std::declval<typename Map::mapped_type>(),
+                void()) {
+
+    cl.def(
+        "__repr__",
+        [name](Map &m) {
+            std::ostringstream s;
+            s << name << '{';
+            bool f = false;
+            for (auto const &kv : m) {
+                if (f) {
+                    s << ", ";
+                }
+                s << kv.first << ": " << kv.second;
+                f = true;
+            }
+            s << '}';
+            return s.str();
+        },
+        "Return the canonical string representation of this map.");
+}
+
+template <typename Map>
+struct keys_view {
+    Map &map;
+};
+
+template <typename Map>
+struct values_view {
+    Map &map;
+};
+
+template <typename Map>
+struct items_view {
+    Map &map;
+};
+
+PYBIND11_NAMESPACE_END(detail)
+
+template <typename Map, typename holder_type = std::unique_ptr<Map>, typename... Args>
+class_<Map, holder_type> bind_map(handle scope, const std::string &name, Args &&...args) {
+    using KeyType = typename Map::key_type;
+    using MappedType = typename Map::mapped_type;
+    using KeysView = detail::keys_view<Map>;
+    using ValuesView = detail::values_view<Map>;
+    using ItemsView = detail::items_view<Map>;
+    using Class_ = class_<Map, holder_type>;
+
+    // If either type is a non-module-local bound type then make the map binding non-local as well;
+    // otherwise (e.g. both types are either module-local or converting) the map will be
+    // module-local.
+    auto *tinfo = detail::get_type_info(typeid(MappedType));
+    bool local = !tinfo || tinfo->module_local;
+    if (local) {
+        tinfo = detail::get_type_info(typeid(KeyType));
+        local = !tinfo || tinfo->module_local;
+    }
+
+    Class_ cl(scope, name.c_str(), pybind11::module_local(local), std::forward<Args>(args)...);
+    class_<KeysView> keys_view(
+        scope, ("KeysView[" + name + "]").c_str(), pybind11::module_local(local));
+    class_<ValuesView> values_view(
+        scope, ("ValuesView[" + name + "]").c_str(), pybind11::module_local(local));
+    class_<ItemsView> items_view(
+        scope, ("ItemsView[" + name + "]").c_str(), pybind11::module_local(local));
+
+    cl.def(init<>());
+
+    // Register stream insertion operator (if possible)
+    detail::map_if_insertion_operator<Map, Class_>(cl, name);
+
+    cl.def(
+        "__bool__",
+        [](const Map &m) -> bool { return !m.empty(); },
+        "Check whether the map is nonempty");
+
+    cl.def(
+        "__iter__",
+        [](Map &m) { return make_key_iterator(m.begin(), m.end()); },
+        keep_alive<0, 1>() /* Essential: keep map alive while iterator exists */
+    );
+
+    cl.def(
+        "keys",
+        [](Map &m) { return KeysView{m}; },
+        keep_alive<0, 1>() /* Essential: keep map alive while view exists */
+    );
+
+    cl.def(
+        "values",
+        [](Map &m) { return ValuesView{m}; },
+        keep_alive<0, 1>() /* Essential: keep map alive while view exists */
+    );
+
+    cl.def(
+        "items",
+        [](Map &m) { return ItemsView{m}; },
+        keep_alive<0, 1>() /* Essential: keep map alive while view exists */
+    );
+
+    cl.def(
+        "__getitem__",
+        [](Map &m, const KeyType &k) -> MappedType & {
+            auto it = m.find(k);
+            if (it == m.end()) {
+                throw key_error();
+            }
+            return it->second;
+        },
+        return_value_policy::reference_internal // ref + keepalive
+    );
+
+    cl.def("__contains__", [](Map &m, const KeyType &k) -> bool {
+        auto it = m.find(k);
+        if (it == m.end()) {
+            return false;
+        }
+        return true;
+    });
+    // Fallback for when the object is not of the key type
+    cl.def("__contains__", [](Map &, const object &) -> bool { return false; });
+
+    // Assignment provided only if the type is copyable
+    detail::map_assignment<Map, Class_>(cl);
+
+    cl.def("__delitem__", [](Map &m, const KeyType &k) {
+        auto it = m.find(k);
+        if (it == m.end()) {
+            throw key_error();
+        }
+        m.erase(it);
+    });
+
+    cl.def("__len__", &Map::size);
+
+    keys_view.def("__len__", [](KeysView &view) { return view.map.size(); });
+    keys_view.def(
+        "__iter__",
+        [](KeysView &view) { return make_key_iterator(view.map.begin(), view.map.end()); },
+        keep_alive<0, 1>() /* Essential: keep view alive while iterator exists */
+    );
+    keys_view.def("__contains__", [](KeysView &view, const KeyType &k) -> bool {
+        auto it = view.map.find(k);
+        if (it == view.map.end()) {
+            return false;
+        }
+        return true;
+    });
+    // Fallback for when the object is not of the key type
+    keys_view.def("__contains__", [](KeysView &, const object &) -> bool { return false; });
+
+    values_view.def("__len__", [](ValuesView &view) { return view.map.size(); });
+    values_view.def(
+        "__iter__",
+        [](ValuesView &view) { return make_value_iterator(view.map.begin(), view.map.end()); },
+        keep_alive<0, 1>() /* Essential: keep view alive while iterator exists */
+    );
+
+    items_view.def("__len__", [](ItemsView &view) { return view.map.size(); });
+    items_view.def(
+        "__iter__",
+        [](ItemsView &view) { return make_iterator(view.map.begin(), view.map.end()); },
+        keep_alive<0, 1>() /* Essential: keep view alive while iterator exists */
+    );
+
+    return cl;
+}
+
+PYBIND11_NAMESPACE_END(PYBIND11_NAMESPACE)

third-party/DPVO/DPViewer/pybind11/noxfile.py

@@ -0,0 +1,97 @@
+import os
+
+import nox
+
+nox.needs_version = ">=2022.1.7"
+nox.options.sessions = ["lint", "tests", "tests_packaging"]
+
+PYTHON_VERISONS = ["3.6", "3.7", "3.8", "3.9", "3.10", "3.11", "pypy3.7", "pypy3.8"]
+
+if os.environ.get("CI", None):
+    nox.options.error_on_missing_interpreters = True
+
+
+@nox.session(reuse_venv=True)
+def lint(session: nox.Session) -> None:
+    """
+    Lint the codebase (except for clang-format/tidy).
+    """
+    session.install("pre-commit")
+    session.run("pre-commit", "run", "-a")
+
+
+@nox.session(python=PYTHON_VERISONS)
+def tests(session: nox.Session) -> None:
+    """
+    Run the tests (requires a compiler).
+    """
+    tmpdir = session.create_tmp()
+    session.install("cmake")
+    session.install("-r", "tests/requirements.txt")
+    session.run(
+        "cmake",
+        "-S.",
+        f"-B{tmpdir}",
+        "-DPYBIND11_WERROR=ON",
+        "-DDOWNLOAD_CATCH=ON",
+        "-DDOWNLOAD_EIGEN=ON",
+        *session.posargs,
+    )
+    session.run("cmake", "--build", tmpdir)
+    session.run("cmake", "--build", tmpdir, "--config=Release", "--target", "check")
+
+
+@nox.session
+def tests_packaging(session: nox.Session) -> None:
+    """
+    Run the packaging tests.
+    """
+
+    session.install("-r", "tests/requirements.txt", "--prefer-binary")
+    session.run("pytest", "tests/extra_python_package")
+
+
+@nox.session(reuse_venv=True)
+def docs(session: nox.Session) -> None:
+    """
+    Build the docs. Pass "serve" to serve.
+    """
+
+    session.install("-r", "docs/requirements.txt")
+    session.chdir("docs")
+
+    if "pdf" in session.posargs:
+        session.run("sphinx-build", "-b", "latexpdf", ".", "_build")
+        return
+
+    session.run("sphinx-build", "-b", "html", ".", "_build")
+
+    if "serve" in session.posargs:
+        session.log("Launching docs at http://localhost:8000/ - use Ctrl-C to quit")
+        session.run("python", "-m", "http.server", "8000", "-d", "_build/html")
+    elif session.posargs:
+        session.error("Unsupported argument to docs")
+
+
+@nox.session(reuse_venv=True)
+def make_changelog(session: nox.Session) -> None:
+    """
+    Inspect the closed issues and make entries for a changelog.
+    """
+    session.install("ghapi", "rich")
+    session.run("python", "tools/make_changelog.py")
+
+
+@nox.session(reuse_venv=True)
+def build(session: nox.Session) -> None:
+    """
+    Build SDists and wheels.
+    """
+
+    session.install("build")
+    session.log("Building normal files")
+    session.run("python", "-m", "build", *session.posargs)
+    session.log("Building pybind11-global files (PYBIND11_GLOBAL_SDIST=1)")
+    session.run(
+        "python", "-m", "build", *session.posargs, env={"PYBIND11_GLOBAL_SDIST": "1"}
+    )

third-party/DPVO/DPViewer/pybind11/pybind11/__init__.py

@@ -0,0 +1,16 @@
+import sys
+
+if sys.version_info < (3, 6):
+    msg = "pybind11 does not support Python < 3.6. 2.9 was the last release supporting Python 2.7 and 3.5."
+    raise ImportError(msg)
+
+
+from ._version import __version__, version_info
+from .commands import get_cmake_dir, get_include
+
+__all__ = (
+    "version_info",
+    "__version__",
+    "get_include",
+    "get_cmake_dir",
+)

third-party/DPVO/DPViewer/pybind11/pybind11/__main__.py

@@ -0,0 +1,49 @@
+# pylint: disable=missing-function-docstring
+
+import argparse
+import sys
+import sysconfig
+
+from .commands import get_cmake_dir, get_include
+
+
+def print_includes() -> None:
+    dirs = [
+        sysconfig.get_path("include"),
+        sysconfig.get_path("platinclude"),
+        get_include(),
+    ]
+
+    # Make unique but preserve order
+    unique_dirs = []
+    for d in dirs:
+        if d and d not in unique_dirs:
+            unique_dirs.append(d)
+
+    print(" ".join("-I" + d for d in unique_dirs))
+
+
+def main() -> None:
+
+    parser = argparse.ArgumentParser()
+    parser.add_argument(
+        "--includes",
+        action="store_true",
+        help="Include flags for both pybind11 and Python headers.",
+    )
+    parser.add_argument(
+        "--cmakedir",
+        action="store_true",
+        help="Print the CMake module directory, ideal for setting -Dpybind11_ROOT in CMake.",
+    )
+    args = parser.parse_args()
+    if not sys.argv[1:]:
+        parser.print_help()
+    if args.includes:
+        print_includes()
+    if args.cmakedir:
+        print(get_cmake_dir())
+
+
+if __name__ == "__main__":
+    main()

third-party/DPVO/DPViewer/pybind11/pybind11/_version.py

@@ -0,0 +1,12 @@
+from typing import Union
+
+
+def _to_int(s: str) -> Union[int, str]:
+    try:
+        return int(s)
+    except ValueError:
+        return s
+
+
+__version__ = "2.10.0.dev1"
+version_info = tuple(_to_int(s) for s in __version__.split("."))

third-party/DPVO/DPViewer/pybind11/pybind11/commands.py

@@ -0,0 +1,25 @@
+import os
+
+DIR = os.path.abspath(os.path.dirname(__file__))
+
+
+def get_include(user: bool = False) -> str:  # pylint: disable=unused-argument
+    """
+    Return the path to the pybind11 include directory. The historical "user"
+    argument is unused, and may be removed.
+    """
+    installed_path = os.path.join(DIR, "include")
+    source_path = os.path.join(os.path.dirname(DIR), "include")
+    return installed_path if os.path.exists(installed_path) else source_path
+
+
+def get_cmake_dir() -> str:
+    """
+    Return the path to the pybind11 CMake module directory.
+    """
+    cmake_installed_path = os.path.join(DIR, "share", "cmake", "pybind11")
+    if os.path.exists(cmake_installed_path):
+        return cmake_installed_path
+
+    msg = "pybind11 not installed, installation required to access the CMake files"
+    raise ImportError(msg)

third-party/DPVO/DPViewer/pybind11/pybind11/setup_helpers.py

@@ -0,0 +1,504 @@
+"""
+This module provides helpers for C++11+ projects using pybind11.
+
+LICENSE:
+
+Copyright (c) 2016 Wenzel Jakob <[email protected]>, All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+1. Redistributions of source code must retain the above copyright notice, this
+   list of conditions and the following disclaimer.
+
+2. Redistributions in binary form must reproduce the above copyright notice,
+   this list of conditions and the following disclaimer in the documentation
+   and/or other materials provided with the distribution.
+
+3. Neither the name of the copyright holder nor the names of its contributors
+   may be used to endorse or promote products derived from this software
+   without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+"""
+
+# IMPORTANT: If you change this file in the pybind11 repo, also review
+# setup_helpers.pyi for matching changes.
+#
+# If you copy this file in, you don't
+# need the .pyi file; it's just an interface file for static type checkers.
+
+import contextlib
+import os
+import platform
+import shlex
+import shutil
+import sys
+import sysconfig
+import tempfile
+import threading
+import warnings
+from functools import lru_cache
+from pathlib import Path
+from typing import (
+    Any,
+    Callable,
+    Dict,
+    Iterable,
+    Iterator,
+    List,
+    Optional,
+    Tuple,
+    TypeVar,
+    Union,
+)
+
+try:
+    from setuptools import Extension as _Extension
+    from setuptools.command.build_ext import build_ext as _build_ext
+except ImportError:
+    from distutils.command.build_ext import build_ext as _build_ext
+    from distutils.extension import Extension as _Extension
+
+import distutils.ccompiler
+import distutils.errors
+
+WIN = sys.platform.startswith("win32") and "mingw" not in sysconfig.get_platform()
+MACOS = sys.platform.startswith("darwin")
+STD_TMPL = "/std:c++{}" if WIN else "-std=c++{}"
+
+
+# It is recommended to use PEP 518 builds if using this module. However, this
+# file explicitly supports being copied into a user's project directory
+# standalone, and pulling pybind11 with the deprecated setup_requires feature.
+# If you copy the file, remember to add it to your MANIFEST.in, and add the current
+# directory into your path if it sits beside your setup.py.
+
+
+class Pybind11Extension(_Extension):  # type: ignore[misc]
+    """
+    Build a C++11+ Extension module with pybind11. This automatically adds the
+    recommended flags when you init the extension and assumes C++ sources - you
+    can further modify the options yourself.
+
+    The customizations are:
+
+    * ``/EHsc`` and ``/bigobj`` on Windows
+    * ``stdlib=libc++`` on macOS
+    * ``visibility=hidden`` and ``-g0`` on Unix
+
+    Finally, you can set ``cxx_std`` via constructor or afterwards to enable
+    flags for C++ std, and a few extra helper flags related to the C++ standard
+    level. It is _highly_ recommended you either set this, or use the provided
+    ``build_ext``, which will search for the highest supported extension for
+    you if the ``cxx_std`` property is not set. Do not set the ``cxx_std``
+    property more than once, as flags are added when you set it. Set the
+    property to None to disable the addition of C++ standard flags.
+
+    If you want to add pybind11 headers manually, for example for an exact
+    git checkout, then set ``include_pybind11=False``.
+    """
+
+    # flags are prepended, so that they can be further overridden, e.g. by
+    # ``extra_compile_args=["-g"]``.
+
+    def _add_cflags(self, flags: List[str]) -> None:
+        self.extra_compile_args[:0] = flags
+
+    def _add_ldflags(self, flags: List[str]) -> None:
+        self.extra_link_args[:0] = flags
+
+    def __init__(self, *args: Any, **kwargs: Any) -> None:
+
+        self._cxx_level = 0
+        cxx_std = kwargs.pop("cxx_std", 0)
+
+        if "language" not in kwargs:
+            kwargs["language"] = "c++"
+
+        include_pybind11 = kwargs.pop("include_pybind11", True)
+
+        super().__init__(*args, **kwargs)
+
+        # Include the installed package pybind11 headers
+        if include_pybind11:
+            # If using setup_requires, this fails the first time - that's okay
+            try:
+                import pybind11
+
+                pyinc = pybind11.get_include()
+
+                if pyinc not in self.include_dirs:
+                    self.include_dirs.append(pyinc)
+            except ModuleNotFoundError:
+                pass
+
+        self.cxx_std = cxx_std
+
+        cflags = []
+        ldflags = []
+        if WIN:
+            cflags += ["/EHsc", "/bigobj"]
+        else:
+            cflags += ["-fvisibility=hidden"]
+            env_cflags = os.environ.get("CFLAGS", "")
+            env_cppflags = os.environ.get("CPPFLAGS", "")
+            c_cpp_flags = shlex.split(env_cflags) + shlex.split(env_cppflags)
+            if not any(opt.startswith("-g") for opt in c_cpp_flags):
+                cflags += ["-g0"]
+            if MACOS:
+                cflags += ["-stdlib=libc++"]
+                ldflags += ["-stdlib=libc++"]
+        self._add_cflags(cflags)
+        self._add_ldflags(ldflags)
+
+    @property
+    def cxx_std(self) -> int:
+        """
+        The CXX standard level. If set, will add the required flags. If left at
+        0, it will trigger an automatic search when pybind11's build_ext is
+        used. If None, will have no effect.  Besides just the flags, this may
+        add a macos-min 10.9 or 10.14 flag if MACOSX_DEPLOYMENT_TARGET is
+        unset.
+        """
+        return self._cxx_level
+
+    @cxx_std.setter
+    def cxx_std(self, level: int) -> None:
+
+        if self._cxx_level:
+            warnings.warn("You cannot safely change the cxx_level after setting it!")
+
+        # MSVC 2015 Update 3 and later only have 14 (and later 17) modes, so
+        # force a valid flag here.
+        if WIN and level == 11:
+            level = 14
+
+        self._cxx_level = level
+
+        if not level:
+            return
+
+        cflags = [STD_TMPL.format(level)]
+        ldflags = []
+
+        if MACOS and "MACOSX_DEPLOYMENT_TARGET" not in os.environ:
+            # C++17 requires a higher min version of macOS. An earlier version
+            # (10.12 or 10.13) can be set manually via environment variable if
+            # you are careful in your feature usage, but 10.14 is the safest
+            # setting for general use. However, never set higher than the
+            # current macOS version!
+            current_macos = tuple(int(x) for x in platform.mac_ver()[0].split(".")[:2])
+            desired_macos = (10, 9) if level < 17 else (10, 14)
+            macos_string = ".".join(str(x) for x in min(current_macos, desired_macos))
+            macosx_min = f"-mmacosx-version-min={macos_string}"
+            cflags += [macosx_min]
+            ldflags += [macosx_min]
+
+        self._add_cflags(cflags)
+        self._add_ldflags(ldflags)
+
+
+# Just in case someone clever tries to multithread
+tmp_chdir_lock = threading.Lock()
+
+
+@contextlib.contextmanager
+def tmp_chdir() -> Iterator[str]:
+    "Prepare and enter a temporary directory, cleanup when done"
+
+    # Threadsafe
+    with tmp_chdir_lock:
+        olddir = os.getcwd()
+        try:
+            tmpdir = tempfile.mkdtemp()
+            os.chdir(tmpdir)
+            yield tmpdir
+        finally:
+            os.chdir(olddir)
+            shutil.rmtree(tmpdir)
+
+
+# cf http://bugs.python.org/issue26689
+def has_flag(compiler: Any, flag: str) -> bool:
+    """
+    Return the flag if a flag name is supported on the
+    specified compiler, otherwise None (can be used as a boolean).
+    If multiple flags are passed, return the first that matches.
+    """
+
+    with tmp_chdir():
+        fname = Path("flagcheck.cpp")
+        # Don't trigger -Wunused-parameter.
+        fname.write_text("int main (int, char **) { return 0; }", encoding="utf-8")
+
+        try:
+            compiler.compile([str(fname)], extra_postargs=[flag])
+        except distutils.errors.CompileError:
+            return False
+        return True
+
+
+# Every call will cache the result
+cpp_flag_cache = None
+
+
+@lru_cache()
+def auto_cpp_level(compiler: Any) -> Union[str, int]:
+    """
+    Return the max supported C++ std level (17, 14, or 11). Returns latest on Windows.
+    """
+
+    if WIN:
+        return "latest"
+
+    levels = [17, 14, 11]
+
+    for level in levels:
+        if has_flag(compiler, STD_TMPL.format(level)):
+            return level
+
+    msg = "Unsupported compiler -- at least C++11 support is needed!"
+    raise RuntimeError(msg)
+
+
+class build_ext(_build_ext):  # type: ignore[misc] # noqa: N801
+    """
+    Customized build_ext that allows an auto-search for the highest supported
+    C++ level for Pybind11Extension. This is only needed for the auto-search
+    for now, and is completely optional otherwise.
+    """
+
+    def build_extensions(self) -> None:
+        """
+        Build extensions, injecting C++ std for Pybind11Extension if needed.
+        """
+
+        for ext in self.extensions:
+            if hasattr(ext, "_cxx_level") and ext._cxx_level == 0:
+                ext.cxx_std = auto_cpp_level(self.compiler)
+
+        super().build_extensions()
+
+
+def intree_extensions(
+    paths: Iterable[str], package_dir: Optional[Dict[str, str]] = None
+) -> List[Pybind11Extension]:
+    """
+    Generate Pybind11Extensions from source files directly located in a Python
+    source tree.
+
+    ``package_dir`` behaves as in ``setuptools.setup``.  If unset, the Python
+    package root parent is determined as the first parent directory that does
+    not contain an ``__init__.py`` file.
+    """
+    exts = []
+
+    if package_dir is None:
+        for path in paths:
+            parent, _ = os.path.split(path)
+            while os.path.exists(os.path.join(parent, "__init__.py")):
+                parent, _ = os.path.split(parent)
+            relname, _ = os.path.splitext(os.path.relpath(path, parent))
+            qualified_name = relname.replace(os.path.sep, ".")
+            exts.append(Pybind11Extension(qualified_name, [path]))
+        return exts
+
+    for path in paths:
+        for prefix, parent in package_dir.items():
+            if path.startswith(parent):
+                relname, _ = os.path.splitext(os.path.relpath(path, parent))
+                qualified_name = relname.replace(os.path.sep, ".")
+                if prefix:
+                    qualified_name = prefix + "." + qualified_name
+                exts.append(Pybind11Extension(qualified_name, [path]))
+                break
+        else:
+            msg = (
+                f"path {path} is not a child of any of the directories listed "
+                f"in 'package_dir' ({package_dir})"
+            )
+            raise ValueError(msg)
+
+    return exts
+
+
+def naive_recompile(obj: str, src: str) -> bool:
+    """
+    This will recompile only if the source file changes. It does not check
+    header files, so a more advanced function or Ccache is better if you have
+    editable header files in your package.
+    """
+    return os.stat(obj).st_mtime < os.stat(src).st_mtime
+
+
+def no_recompile(obg: str, src: str) -> bool:  # pylint: disable=unused-argument
+    """
+    This is the safest but slowest choice (and is the default) - will always
+    recompile sources.
+    """
+    return True
+
+
+S = TypeVar("S", bound="ParallelCompile")
+
+CCompilerMethod = Callable[
+    [
+        distutils.ccompiler.CCompiler,
+        List[str],
+        Optional[str],
+        Optional[Union[Tuple[str], Tuple[str, Optional[str]]]],
+        Optional[List[str]],
+        bool,
+        Optional[List[str]],
+        Optional[List[str]],
+        Optional[List[str]],
+    ],
+    List[str],
+]
+
+
+# Optional parallel compile utility
+# inspired by: http://stackoverflow.com/questions/11013851/speeding-up-build-process-with-distutils
+# and: https://github.com/tbenthompson/cppimport/blob/stable/cppimport/build_module.py
+# and NumPy's parallel distutils module:
+#              https://github.com/numpy/numpy/blob/master/numpy/distutils/ccompiler.py
+class ParallelCompile:
+    """
+    Make a parallel compile function. Inspired by
+    numpy.distutils.ccompiler.CCompiler.compile and cppimport.
+
+    This takes several arguments that allow you to customize the compile
+    function created:
+
+    envvar:
+        Set an environment variable to control the compilation threads, like
+        NPY_NUM_BUILD_JOBS
+    default:
+        0 will automatically multithread, or 1 will only multithread if the
+        envvar is set.
+    max:
+        The limit for automatic multithreading if non-zero
+    needs_recompile:
+        A function of (obj, src) that returns True when recompile is needed.  No
+        effect in isolated mode; use ccache instead, see
+        https://github.com/matplotlib/matplotlib/issues/1507/
+
+    To use::
+
+        ParallelCompile("NPY_NUM_BUILD_JOBS").install()
+
+    or::
+
+        with ParallelCompile("NPY_NUM_BUILD_JOBS"):
+            setup(...)
+
+    By default, this assumes all files need to be recompiled. A smarter
+    function can be provided via needs_recompile.  If the output has not yet
+    been generated, the compile will always run, and this function is not
+    called.
+    """
+
+    __slots__ = ("envvar", "default", "max", "_old", "needs_recompile")
+
+    def __init__(
+        self,
+        envvar: Optional[str] = None,
+        default: int = 0,
+        max: int = 0,  # pylint: disable=redefined-builtin
+        needs_recompile: Callable[[str, str], bool] = no_recompile,
+    ) -> None:
+        self.envvar = envvar
+        self.default = default
+        self.max = max
+        self.needs_recompile = needs_recompile
+        self._old: List[CCompilerMethod] = []
+
+    def function(self) -> CCompilerMethod:
+        """
+        Builds a function object usable as distutils.ccompiler.CCompiler.compile.
+        """
+
+        def compile_function(
+            compiler: distutils.ccompiler.CCompiler,
+            sources: List[str],
+            output_dir: Optional[str] = None,
+            macros: Optional[Union[Tuple[str], Tuple[str, Optional[str]]]] = None,
+            include_dirs: Optional[List[str]] = None,
+            debug: bool = False,
+            extra_preargs: Optional[List[str]] = None,
+            extra_postargs: Optional[List[str]] = None,
+            depends: Optional[List[str]] = None,
+        ) -> Any:
+
+            # These lines are directly from distutils.ccompiler.CCompiler
+            macros, objects, extra_postargs, pp_opts, build = compiler._setup_compile(  # type: ignore[attr-defined]
+                output_dir, macros, include_dirs, sources, depends, extra_postargs
+            )
+            cc_args = compiler._get_cc_args(pp_opts, debug, extra_preargs)  # type: ignore[attr-defined]
+
+            # The number of threads; start with default.
+            threads = self.default
+
+            # Determine the number of compilation threads, unless set by an environment variable.
+            if self.envvar is not None:
+                threads = int(os.environ.get(self.envvar, self.default))
+
+            def _single_compile(obj: Any) -> None:
+                try:
+                    src, ext = build[obj]
+                except KeyError:
+                    return
+
+                if not os.path.exists(obj) or self.needs_recompile(obj, src):
+                    compiler._compile(obj, src, ext, cc_args, extra_postargs, pp_opts)  # type: ignore[attr-defined]
+
+            try:
+                # Importing .synchronize checks for platforms that have some multiprocessing
+                # capabilities but lack semaphores, such as AWS Lambda and Android Termux.
+                import multiprocessing.synchronize
+                from multiprocessing.pool import ThreadPool
+            except ImportError:
+                threads = 1
+
+            if threads == 0:
+                try:
+                    threads = multiprocessing.cpu_count()
+                    threads = self.max if self.max and self.max < threads else threads
+                except NotImplementedError:
+                    threads = 1
+
+            if threads > 1:
+                with ThreadPool(threads) as pool:
+                    for _ in pool.imap_unordered(_single_compile, objects):
+                        pass
+            else:
+                for ob in objects:
+                    _single_compile(ob)
+
+            return objects
+
+        return compile_function
+
+    def install(self: S) -> S:
+        """
+        Installs the compile function into distutils.ccompiler.CCompiler.compile.
+        """
+        distutils.ccompiler.CCompiler.compile = self.function()  # type: ignore[assignment]
+        return self
+
+    def __enter__(self: S) -> S:
+        self._old.append(distutils.ccompiler.CCompiler.compile)
+        return self.install()
+
+    def __exit__(self, *args: Any) -> None:
+        distutils.ccompiler.CCompiler.compile = self._old.pop()  # type: ignore[assignment]

third-party/DPVO/DPViewer/pybind11/pyproject.toml

@@ -0,0 +1,61 @@
+[build-system]
+requires = ["setuptools>=42", "cmake>=3.18", "ninja"]
+build-backend = "setuptools.build_meta"
+
+[tool.check-manifest]
+ignore = [
+    "tests/**",
+    "docs/**",
+    "tools/**",
+    "include/**",
+    ".*",
+    "pybind11/include/**",
+    "pybind11/share/**",
+    "CMakeLists.txt",
+    "noxfile.py",
+]
+
+[tool.isort]
+# Needs the compiled .so modules and env.py from tests
+known_first_party = "env,pybind11_cross_module_tests,pybind11_tests,"
+# For black compatibility
+profile = "black"
+
+[tool.mypy]
+files = ["pybind11"]
+python_version = "3.6"
+strict = true
+show_error_codes = true
+enable_error_code = ["ignore-without-code", "redundant-expr", "truthy-bool"]
+warn_unreachable = true
+
+[[tool.mypy.overrides]]
+module = ["ghapi.*", "setuptools.*"]
+ignore_missing_imports = true
+
+
+[tool.pytest.ini_options]
+minversion = "6.0"
+addopts = ["-ra", "--showlocals", "--strict-markers", "--strict-config"]
+xfail_strict = true
+filterwarnings = ["error"]
+log_cli_level = "info"
+testpaths = [
+    "tests",
+]
+timeout=300
+
+
+[tool.pylint]
+master.py-version = "3.6"
+reports.output-format = "colorized"
+messages_control.disable = [
+  "design",
+  "fixme",
+  "imports",
+  "line-too-long",
+  "imports",
+  "invalid-name",
+  "protected-access",
+  "missing-module-docstring",
+]

third-party/DPVO/DPViewer/pybind11/setup.cfg

@@ -0,0 +1,49 @@
+[metadata]
+long_description = file: README.rst
+long_description_content_type = text/x-rst
+description = Seamless operability between C++11 and Python
+author = Wenzel Jakob
+author_email = [email protected]
+url = https://github.com/pybind/pybind11
+license = BSD
+
+classifiers =
+    Development Status :: 5 - Production/Stable
+    Intended Audience :: Developers
+    Topic :: Software Development :: Libraries :: Python Modules
+    Topic :: Utilities
+    Programming Language :: C++
+    Programming Language :: Python :: 3 :: Only
+    Programming Language :: Python :: 3.6
+    Programming Language :: Python :: 3.7
+    Programming Language :: Python :: 3.8
+    Programming Language :: Python :: 3.9
+    Programming Language :: Python :: 3.10
+    License :: OSI Approved :: BSD License
+    Programming Language :: Python :: Implementation :: PyPy
+    Programming Language :: Python :: Implementation :: CPython
+    Programming Language :: C++
+    Topic :: Software Development :: Libraries :: Python Modules
+
+keywords =
+    C++11
+    Python bindings
+
+project_urls =
+    Documentation = https://pybind11.readthedocs.io/
+    Bug Tracker = https://github.com/pybind/pybind11/issues
+    Discussions = https://github.com/pybind/pybind11/discussions
+    Changelog = https://pybind11.readthedocs.io/en/latest/changelog.html
+    Chat = https://gitter.im/pybind/Lobby
+
+[options]
+python_requires = >=3.6
+zip_safe = False
+
+
+[flake8]
+max-line-length = 120
+show_source = True
+exclude = .git, __pycache__, build, dist, docs, tools, venv
+extend-ignore = E203, E722, B950
+extend-select = B9

third-party/DPVO/DPViewer/pybind11/setup.py

@@ -0,0 +1,149 @@
+#!/usr/bin/env python3
+
+# Setup script for PyPI; use CMakeFile.txt to build extension modules
+
+import contextlib
+import os
+import re
+import shutil
+import string
+import subprocess
+import sys
+from pathlib import Path
+from tempfile import TemporaryDirectory
+from typing import Dict, Iterator, List, Union
+
+import setuptools.command.sdist
+
+DIR = Path(__file__).parent.absolute()
+VERSION_REGEX = re.compile(
+    r"^\s*#\s*define\s+PYBIND11_VERSION_([A-Z]+)\s+(.*)$", re.MULTILINE
+)
+VERSION_FILE = Path("pybind11/_version.py")
+COMMON_FILE = Path("include/pybind11/detail/common.h")
+
+
+def build_expected_version_hex(matches: Dict[str, str]) -> str:
+    patch_level_serial = matches["PATCH"]
+    serial = None
+    major = int(matches["MAJOR"])
+    minor = int(matches["MINOR"])
+    flds = patch_level_serial.split(".")
+    if flds:
+        patch = int(flds[0])
+        if len(flds) == 1:
+            level = "0"
+            serial = 0
+        elif len(flds) == 2:
+            level_serial = flds[1]
+            for level in ("a", "b", "c", "dev"):
+                if level_serial.startswith(level):
+                    serial = int(level_serial[len(level) :])
+                    break
+    if serial is None:
+        msg = f'Invalid PYBIND11_VERSION_PATCH: "{patch_level_serial}"'
+        raise RuntimeError(msg)
+    version_hex_str = f"{major:02x}{minor:02x}{patch:02x}{level[:1]}{serial:x}"
+    return f"0x{version_hex_str.upper()}"
+
+
+# PYBIND11_GLOBAL_SDIST will build a different sdist, with the python-headers
+# files, and the sys.prefix files (CMake and headers).
+
+global_sdist = os.environ.get("PYBIND11_GLOBAL_SDIST", False)
+
+setup_py = Path(
+    "tools/setup_global.py.in" if global_sdist else "tools/setup_main.py.in"
+)
+extra_cmd = 'cmdclass["sdist"] = SDist\n'
+
+to_src = (
+    (Path("pyproject.toml"), Path("tools/pyproject.toml")),
+    (Path("setup.py"), setup_py),
+)
+
+
+# Read the listed version
+loc: Dict[str, str] = {}
+code = compile(VERSION_FILE.read_text(encoding="utf-8"), "pybind11/_version.py", "exec")
+exec(code, loc)
+version = loc["__version__"]
+
+# Verify that the version matches the one in C++
+matches = dict(VERSION_REGEX.findall(COMMON_FILE.read_text(encoding="utf8")))
+cpp_version = "{MAJOR}.{MINOR}.{PATCH}".format(**matches)
+if version != cpp_version:
+    msg = f"Python version {version} does not match C++ version {cpp_version}!"
+    raise RuntimeError(msg)
+
+version_hex = matches.get("HEX", "MISSING")
+exp_version_hex = build_expected_version_hex(matches)
+if version_hex != exp_version_hex:
+    msg = f"PYBIND11_VERSION_HEX {version_hex} does not match expected value {exp_version_hex}!"
+    raise RuntimeError(msg)
+
+
+# TODO: use literals & overload (typing extensions or Python 3.8)
+def get_and_replace(
+    filename: Path, binary: bool = False, **opts: str
+) -> Union[bytes, str]:
+    if binary:
+        contents = filename.read_bytes()
+        return string.Template(contents.decode()).substitute(opts).encode()
+
+    return string.Template(filename.read_text()).substitute(opts)
+
+
+# Use our input files instead when making the SDist (and anything that depends
+# on it, like a wheel)
+class SDist(setuptools.command.sdist.sdist):  # type: ignore[misc]
+    def make_release_tree(self, base_dir: str, files: List[str]) -> None:
+        super().make_release_tree(base_dir, files)
+
+        for to, src in to_src:
+            txt = get_and_replace(src, binary=True, version=version, extra_cmd="")
+
+            dest = Path(base_dir) / to
+
+            # This is normally linked, so unlink before writing!
+            dest.unlink()
+            dest.write_bytes(txt)  # type: ignore[arg-type]
+
+
+# Remove the CMake install directory when done
+@contextlib.contextmanager
+def remove_output(*sources: str) -> Iterator[None]:
+    try:
+        yield
+    finally:
+        for src in sources:
+            shutil.rmtree(src)
+
+
+with remove_output("pybind11/include", "pybind11/share"):
+    # Generate the files if they are not present.
+    with TemporaryDirectory() as tmpdir:
+        cmd = ["cmake", "-S", ".", "-B", tmpdir] + [
+            "-DCMAKE_INSTALL_PREFIX=pybind11",
+            "-DBUILD_TESTING=OFF",
+            "-DPYBIND11_NOPYTHON=ON",
+        ]
+        if "CMAKE_ARGS" in os.environ:
+            fcommand = [
+                c
+                for c in os.environ["CMAKE_ARGS"].split()
+                if "DCMAKE_INSTALL_PREFIX" not in c
+            ]
+            cmd += fcommand
+        subprocess.run(cmd, check=True, cwd=DIR, stdout=sys.stdout, stderr=sys.stderr)
+        subprocess.run(
+            ["cmake", "--install", tmpdir],
+            check=True,
+            cwd=DIR,
+            stdout=sys.stdout,
+            stderr=sys.stderr,
+        )
+
+    txt = get_and_replace(setup_py, version=version, extra_cmd=extra_cmd)
+    code = compile(txt, setup_py, "exec")
+    exec(code, {"SDist": SDist})

third-party/DPVO/DPViewer/pybind11/tools/FindCatch.cmake

@@ -0,0 +1,72 @@
+# - Find the Catch test framework or download it (single header)
+#
+# This is a quick module for internal use. It assumes that Catch is
+# REQUIRED and that a minimum version is provided (not EXACT). If
+# a suitable version isn't found locally, the single header file
+# will be downloaded and placed in the build dir: PROJECT_BINARY_DIR.
+#
+# This code sets the following variables:
+#  CATCH_INCLUDE_DIR      - path to catch.hpp
+#  CATCH_VERSION          - version number
+
+option(DOWNLOAD_CATCH "Download catch2 if not found")
+
+if(NOT Catch_FIND_VERSION)
+  message(FATAL_ERROR "A version number must be specified.")
+elseif(Catch_FIND_REQUIRED)
+  message(FATAL_ERROR "This module assumes Catch is not required.")
+elseif(Catch_FIND_VERSION_EXACT)
+  message(FATAL_ERROR "Exact version numbers are not supported, only minimum.")
+endif()
+
+# Extract the version number from catch.hpp
+function(_get_catch_version)
+  file(
+    STRINGS "${CATCH_INCLUDE_DIR}/catch.hpp" version_line
+    REGEX "Catch v.*"
+    LIMIT_COUNT 1)
+  if(version_line MATCHES "Catch v([0-9]+)\\.([0-9]+)\\.([0-9]+)")
+    set(CATCH_VERSION
+        "${CMAKE_MATCH_1}.${CMAKE_MATCH_2}.${CMAKE_MATCH_3}"
+        PARENT_SCOPE)
+  endif()
+endfunction()
+
+# Download the single-header version of Catch
+function(_download_catch version destination_dir)
+  message(STATUS "Downloading catch v${version}...")
+  set(url https://github.com/philsquared/Catch/releases/download/v${version}/catch.hpp)
+  file(DOWNLOAD ${url} "${destination_dir}/catch.hpp" STATUS status)
+  list(GET status 0 error)
+  if(error)
+    message(FATAL_ERROR "Could not download ${url}")
+  endif()
+  set(CATCH_INCLUDE_DIR
+      "${destination_dir}"
+      CACHE INTERNAL "")
+endfunction()
+
+# Look for catch locally
+find_path(
+  CATCH_INCLUDE_DIR
+  NAMES catch.hpp
+  PATH_SUFFIXES catch2)
+if(CATCH_INCLUDE_DIR)
+  _get_catch_version()
+endif()
+
+# Download the header if it wasn't found or if it's outdated
+if(NOT CATCH_VERSION OR CATCH_VERSION VERSION_LESS ${Catch_FIND_VERSION})
+  if(DOWNLOAD_CATCH)
+    _download_catch(${Catch_FIND_VERSION} "${PROJECT_BINARY_DIR}/catch/")
+    _get_catch_version()
+  else()
+    set(CATCH_FOUND FALSE)
+    return()
+  endif()
+endif()
+
+add_library(Catch2::Catch2 IMPORTED INTERFACE)
+set_property(TARGET Catch2::Catch2 PROPERTY INTERFACE_INCLUDE_DIRECTORIES "${CATCH_INCLUDE_DIR}")
+
+set(CATCH_FOUND TRUE)

third-party/DPVO/DPViewer/pybind11/tools/FindEigen3.cmake

@@ -0,0 +1,86 @@
+# - Try to find Eigen3 lib
+#
+# This module supports requiring a minimum version, e.g. you can do
+#   find_package(Eigen3 3.1.2)
+# to require version 3.1.2 or newer of Eigen3.
+#
+# Once done this will define
+#
+#  EIGEN3_FOUND - system has eigen lib with correct version
+#  EIGEN3_INCLUDE_DIR - the eigen include directory
+#  EIGEN3_VERSION - eigen version
+
+# Copyright (c) 2006, 2007 Montel Laurent, <[email protected]>
+# Copyright (c) 2008, 2009 Gael Guennebaud, <[email protected]>
+# Copyright (c) 2009 Benoit Jacob <[email protected]>
+# Redistribution and use is allowed according to the terms of the 2-clause BSD license.
+
+if(NOT Eigen3_FIND_VERSION)
+  if(NOT Eigen3_FIND_VERSION_MAJOR)
+    set(Eigen3_FIND_VERSION_MAJOR 2)
+  endif(NOT Eigen3_FIND_VERSION_MAJOR)
+  if(NOT Eigen3_FIND_VERSION_MINOR)
+    set(Eigen3_FIND_VERSION_MINOR 91)
+  endif(NOT Eigen3_FIND_VERSION_MINOR)
+  if(NOT Eigen3_FIND_VERSION_PATCH)
+    set(Eigen3_FIND_VERSION_PATCH 0)
+  endif(NOT Eigen3_FIND_VERSION_PATCH)
+
+  set(Eigen3_FIND_VERSION
+      "${Eigen3_FIND_VERSION_MAJOR}.${Eigen3_FIND_VERSION_MINOR}.${Eigen3_FIND_VERSION_PATCH}")
+endif(NOT Eigen3_FIND_VERSION)
+
+macro(_eigen3_check_version)
+  file(READ "${EIGEN3_INCLUDE_DIR}/Eigen/src/Core/util/Macros.h" _eigen3_version_header)
+
+  string(REGEX MATCH "define[ \t]+EIGEN_WORLD_VERSION[ \t]+([0-9]+)" _eigen3_world_version_match
+               "${_eigen3_version_header}")
+  set(EIGEN3_WORLD_VERSION "${CMAKE_MATCH_1}")
+  string(REGEX MATCH "define[ \t]+EIGEN_MAJOR_VERSION[ \t]+([0-9]+)" _eigen3_major_version_match
+               "${_eigen3_version_header}")
+  set(EIGEN3_MAJOR_VERSION "${CMAKE_MATCH_1}")
+  string(REGEX MATCH "define[ \t]+EIGEN_MINOR_VERSION[ \t]+([0-9]+)" _eigen3_minor_version_match
+               "${_eigen3_version_header}")
+  set(EIGEN3_MINOR_VERSION "${CMAKE_MATCH_1}")
+
+  set(EIGEN3_VERSION ${EIGEN3_WORLD_VERSION}.${EIGEN3_MAJOR_VERSION}.${EIGEN3_MINOR_VERSION})
+  if(${EIGEN3_VERSION} VERSION_LESS ${Eigen3_FIND_VERSION})
+    set(EIGEN3_VERSION_OK FALSE)
+  else(${EIGEN3_VERSION} VERSION_LESS ${Eigen3_FIND_VERSION})
+    set(EIGEN3_VERSION_OK TRUE)
+  endif(${EIGEN3_VERSION} VERSION_LESS ${Eigen3_FIND_VERSION})
+
+  if(NOT EIGEN3_VERSION_OK)
+
+    message(STATUS "Eigen3 version ${EIGEN3_VERSION} found in ${EIGEN3_INCLUDE_DIR}, "
+                   "but at least version ${Eigen3_FIND_VERSION} is required")
+  endif(NOT EIGEN3_VERSION_OK)
+endmacro(_eigen3_check_version)
+
+if(EIGEN3_INCLUDE_DIR)
+
+  # in cache already
+  _eigen3_check_version()
+  set(EIGEN3_FOUND ${EIGEN3_VERSION_OK})
+
+else(EIGEN3_INCLUDE_DIR)
+  if(NOT DEFINED KDE4_INCLUDE_DIR)
+    set(KDE4_INCLUDE_DIR "")
+  endif()
+
+  find_path(
+    EIGEN3_INCLUDE_DIR
+    NAMES signature_of_eigen3_matrix_library
+    PATHS ${CMAKE_INSTALL_PREFIX}/include ${KDE4_INCLUDE_DIR}
+    PATH_SUFFIXES eigen3 eigen)
+
+  if(EIGEN3_INCLUDE_DIR)
+    _eigen3_check_version()
+  endif(EIGEN3_INCLUDE_DIR)
+
+  include(FindPackageHandleStandardArgs)
+  find_package_handle_standard_args(Eigen3 DEFAULT_MSG EIGEN3_INCLUDE_DIR EIGEN3_VERSION_OK)
+
+  mark_as_advanced(EIGEN3_INCLUDE_DIR)
+
+endif(EIGEN3_INCLUDE_DIR)

third-party/DPVO/DPViewer/pybind11/tools/FindPythonLibsNew.cmake

@@ -0,0 +1,281 @@
+# - Find python libraries
+# This module finds the libraries corresponding to the Python interpreter
+# FindPythonInterp provides.
+# This code sets the following variables:
+#
+#  PYTHONLIBS_FOUND           - have the Python libs been found
+#  PYTHON_PREFIX              - path to the Python installation
+#  PYTHON_LIBRARIES           - path to the python library
+#  PYTHON_INCLUDE_DIRS        - path to where Python.h is found
+#  PYTHON_MODULE_EXTENSION    - lib extension, e.g. '.so' or '.pyd'
+#  PYTHON_MODULE_PREFIX       - lib name prefix: usually an empty string
+#  PYTHON_SITE_PACKAGES       - path to installation site-packages
+#  PYTHON_IS_DEBUG            - whether the Python interpreter is a debug build
+#
+# Thanks to talljimbo for the patch adding the 'LDVERSION' config
+# variable usage.
+
+#=============================================================================
+# Copyright 2001-2009 Kitware, Inc.
+# Copyright 2012 Continuum Analytics, Inc.
+#
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#
+# * Redistributions in binary form must reproduce the above copyright
+# notice, this list of conditions and the following disclaimer in the
+# documentation and/or other materials provided with the distribution.
+#
+# * Neither the names of Kitware, Inc., the Insight Software Consortium,
+# nor the names of their contributors may be used to endorse or promote
+# products derived from this software without specific prior written
+# permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# # A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+#=============================================================================
+
+# Checking for the extension makes sure that `LibsNew` was found and not just `Libs`.
+if(PYTHONLIBS_FOUND AND PYTHON_MODULE_EXTENSION)
+  return()
+endif()
+
+if(PythonLibsNew_FIND_QUIETLY)
+  set(_pythonlibs_quiet QUIET)
+else()
+  set(_pythonlibs_quiet "")
+endif()
+
+if(PythonLibsNew_FIND_REQUIRED)
+  set(_pythonlibs_required REQUIRED)
+endif()
+
+# Check to see if the `python` command is present and from a virtual
+# environment, conda, or GHA activation - if it is, try to use that.
+
+if(NOT DEFINED PYTHON_EXECUTABLE)
+  if(DEFINED ENV{VIRTUAL_ENV})
+    find_program(
+      PYTHON_EXECUTABLE python
+      PATHS "$ENV{VIRTUAL_ENV}" "$ENV{VIRTUAL_ENV}/bin"
+      NO_DEFAULT_PATH)
+  elseif(DEFINED ENV{CONDA_PREFIX})
+    find_program(
+      PYTHON_EXECUTABLE python
+      PATHS "$ENV{CONDA_PREFIX}" "$ENV{CONDA_PREFIX}/bin"
+      NO_DEFAULT_PATH)
+  elseif(DEFINED ENV{pythonLocation})
+    find_program(
+      PYTHON_EXECUTABLE python
+      PATHS "$ENV{pythonLocation}" "$ENV{pythonLocation}/bin"
+      NO_DEFAULT_PATH)
+  endif()
+  if(NOT PYTHON_EXECUTABLE)
+    unset(PYTHON_EXECUTABLE)
+  endif()
+endif()
+
+# Use the Python interpreter to find the libs.
+if(NOT PythonLibsNew_FIND_VERSION)
+  set(PythonLibsNew_FIND_VERSION "3.6")
+endif()
+
+find_package(PythonInterp ${PythonLibsNew_FIND_VERSION} ${_pythonlibs_required}
+             ${_pythonlibs_quiet})
+
+if(NOT PYTHONINTERP_FOUND)
+  set(PYTHONLIBS_FOUND FALSE)
+  set(PythonLibsNew_FOUND FALSE)
+  return()
+endif()
+
+# According to https://stackoverflow.com/questions/646518/python-how-to-detect-debug-interpreter
+# testing whether sys has the gettotalrefcount function is a reliable, cross-platform
+# way to detect a CPython debug interpreter.
+#
+# The library suffix is from the config var LDVERSION sometimes, otherwise
+# VERSION. VERSION will typically be like "2.7" on unix, and "27" on windows.
+execute_process(
+  COMMAND
+    "${PYTHON_EXECUTABLE}" "-c" "
+import sys;import struct;
+import sysconfig as s
+USE_SYSCONFIG = sys.version_info >= (3, 10)
+if not USE_SYSCONFIG:
+    from distutils import sysconfig as ds
+print('.'.join(str(v) for v in sys.version_info));
+print(sys.prefix);
+if USE_SYSCONFIG:
+    scheme = s.get_default_scheme()
+    if scheme == 'posix_local':
+        # Debian's default scheme installs to /usr/local/ but we want to find headers in /usr/
+        scheme = 'posix_prefix'
+    print(s.get_path('platinclude', scheme))
+    print(s.get_path('platlib'))
+    print(s.get_config_var('EXT_SUFFIX') or s.get_config_var('SO'))
+else:
+    print(ds.get_python_inc(plat_specific=True));
+    print(ds.get_python_lib(plat_specific=True));
+    print(ds.get_config_var('EXT_SUFFIX') or ds.get_config_var('SO'));
+print(hasattr(sys, 'gettotalrefcount')+0);
+print(struct.calcsize('@P'));
+print(s.get_config_var('LDVERSION') or s.get_config_var('VERSION'));
+print(s.get_config_var('LIBDIR') or '');
+print(s.get_config_var('MULTIARCH') or '');
+"
+  RESULT_VARIABLE _PYTHON_SUCCESS
+  OUTPUT_VARIABLE _PYTHON_VALUES
+  ERROR_VARIABLE _PYTHON_ERROR_VALUE)
+
+if(NOT _PYTHON_SUCCESS MATCHES 0)
+  if(PythonLibsNew_FIND_REQUIRED)
+    message(FATAL_ERROR "Python config failure:\n${_PYTHON_ERROR_VALUE}")
+  endif()
+  set(PYTHONLIBS_FOUND FALSE)
+  set(PythonLibsNew_FOUND FALSE)
+  return()
+endif()
+
+# Can manually set values when cross-compiling
+macro(_PYBIND11_GET_IF_UNDEF lst index name)
+  if(NOT DEFINED "${name}")
+    list(GET "${lst}" "${index}" "${name}")
+  endif()
+endmacro()
+
+# Convert the process output into a list
+if(WIN32)
+  string(REGEX REPLACE "\\\\" "/" _PYTHON_VALUES ${_PYTHON_VALUES})
+endif()
+string(REGEX REPLACE ";" "\\\\;" _PYTHON_VALUES ${_PYTHON_VALUES})
+string(REGEX REPLACE "\n" ";" _PYTHON_VALUES ${_PYTHON_VALUES})
+_pybind11_get_if_undef(_PYTHON_VALUES 0 _PYTHON_VERSION_LIST)
+_pybind11_get_if_undef(_PYTHON_VALUES 1 PYTHON_PREFIX)
+_pybind11_get_if_undef(_PYTHON_VALUES 2 PYTHON_INCLUDE_DIR)
+_pybind11_get_if_undef(_PYTHON_VALUES 3 PYTHON_SITE_PACKAGES)
+_pybind11_get_if_undef(_PYTHON_VALUES 4 PYTHON_MODULE_EXTENSION)
+_pybind11_get_if_undef(_PYTHON_VALUES 5 PYTHON_IS_DEBUG)
+_pybind11_get_if_undef(_PYTHON_VALUES 6 PYTHON_SIZEOF_VOID_P)
+_pybind11_get_if_undef(_PYTHON_VALUES 7 PYTHON_LIBRARY_SUFFIX)
+_pybind11_get_if_undef(_PYTHON_VALUES 8 PYTHON_LIBDIR)
+_pybind11_get_if_undef(_PYTHON_VALUES 9 PYTHON_MULTIARCH)
+
+# Make sure the Python has the same pointer-size as the chosen compiler
+# Skip if CMAKE_SIZEOF_VOID_P is not defined
+# This should be skipped for (non-Apple) cross-compiles (like EMSCRIPTEN)
+if(NOT CMAKE_CROSSCOMPILING
+   AND CMAKE_SIZEOF_VOID_P
+   AND (NOT "${PYTHON_SIZEOF_VOID_P}" STREQUAL "${CMAKE_SIZEOF_VOID_P}"))
+  if(PythonLibsNew_FIND_REQUIRED)
+    math(EXPR _PYTHON_BITS "${PYTHON_SIZEOF_VOID_P} * 8")
+    math(EXPR _CMAKE_BITS "${CMAKE_SIZEOF_VOID_P} * 8")
+    message(FATAL_ERROR "Python config failure: Python is ${_PYTHON_BITS}-bit, "
+                        "chosen compiler is  ${_CMAKE_BITS}-bit")
+  endif()
+  set(PYTHONLIBS_FOUND FALSE)
+  set(PythonLibsNew_FOUND FALSE)
+  return()
+endif()
+
+# The built-in FindPython didn't always give the version numbers
+string(REGEX REPLACE "\\." ";" _PYTHON_VERSION_LIST ${_PYTHON_VERSION_LIST})
+list(GET _PYTHON_VERSION_LIST 0 PYTHON_VERSION_MAJOR)
+list(GET _PYTHON_VERSION_LIST 1 PYTHON_VERSION_MINOR)
+list(GET _PYTHON_VERSION_LIST 2 PYTHON_VERSION_PATCH)
+set(PYTHON_VERSION "${PYTHON_VERSION_MAJOR}.${PYTHON_VERSION_MINOR}.${PYTHON_VERSION_PATCH}")
+
+# Make sure all directory separators are '/'
+string(REGEX REPLACE "\\\\" "/" PYTHON_PREFIX "${PYTHON_PREFIX}")
+string(REGEX REPLACE "\\\\" "/" PYTHON_INCLUDE_DIR "${PYTHON_INCLUDE_DIR}")
+string(REGEX REPLACE "\\\\" "/" PYTHON_SITE_PACKAGES "${PYTHON_SITE_PACKAGES}")
+
+if(CMAKE_HOST_WIN32)
+  set(PYTHON_LIBRARY "${PYTHON_PREFIX}/libs/python${PYTHON_LIBRARY_SUFFIX}.lib")
+
+  # when run in a venv, PYTHON_PREFIX points to it. But the libraries remain in the
+  # original python installation. They may be found relative to PYTHON_INCLUDE_DIR.
+  if(NOT EXISTS "${PYTHON_LIBRARY}")
+    get_filename_component(_PYTHON_ROOT ${PYTHON_INCLUDE_DIR} DIRECTORY)
+    set(PYTHON_LIBRARY "${_PYTHON_ROOT}/libs/python${PYTHON_LIBRARY_SUFFIX}.lib")
+  endif()
+
+  # if we are in MSYS & MINGW, and we didn't find windows python lib, look for system python lib
+  if(DEFINED ENV{MSYSTEM}
+     AND MINGW
+     AND NOT EXISTS "${PYTHON_LIBRARY}")
+    if(PYTHON_MULTIARCH)
+      set(_PYTHON_LIBS_SEARCH "${PYTHON_LIBDIR}/${PYTHON_MULTIARCH}" "${PYTHON_LIBDIR}")
+    else()
+      set(_PYTHON_LIBS_SEARCH "${PYTHON_LIBDIR}")
+    endif()
+    unset(PYTHON_LIBRARY)
+    find_library(
+      PYTHON_LIBRARY
+      NAMES "python${PYTHON_LIBRARY_SUFFIX}"
+      PATHS ${_PYTHON_LIBS_SEARCH}
+      NO_DEFAULT_PATH)
+  endif()
+
+  # raise an error if the python libs are still not found.
+  if(NOT EXISTS "${PYTHON_LIBRARY}")
+    message(FATAL_ERROR "Python libraries not found")
+  endif()
+
+else()
+  if(PYTHON_MULTIARCH)
+    set(_PYTHON_LIBS_SEARCH "${PYTHON_LIBDIR}/${PYTHON_MULTIARCH}" "${PYTHON_LIBDIR}")
+  else()
+    set(_PYTHON_LIBS_SEARCH "${PYTHON_LIBDIR}")
+  endif()
+  #message(STATUS "Searching for Python libs in ${_PYTHON_LIBS_SEARCH}")
+  # Probably this needs to be more involved. It would be nice if the config
+  # information the python interpreter itself gave us were more complete.
+  find_library(
+    PYTHON_LIBRARY
+    NAMES "python${PYTHON_LIBRARY_SUFFIX}"
+    PATHS ${_PYTHON_LIBS_SEARCH}
+    NO_DEFAULT_PATH)
+
+  # If all else fails, just set the name/version and let the linker figure out the path.
+  if(NOT PYTHON_LIBRARY)
+    set(PYTHON_LIBRARY python${PYTHON_LIBRARY_SUFFIX})
+  endif()
+endif()
+
+mark_as_advanced(PYTHON_LIBRARY PYTHON_INCLUDE_DIR)
+
+# We use PYTHON_INCLUDE_DIR, PYTHON_LIBRARY and PYTHON_DEBUG_LIBRARY for the
+# cache entries because they are meant to specify the location of a single
+# library. We now set the variables listed by the documentation for this
+# module.
+set(PYTHON_INCLUDE_DIRS "${PYTHON_INCLUDE_DIR}")
+set(PYTHON_LIBRARIES "${PYTHON_LIBRARY}")
+if(NOT PYTHON_DEBUG_LIBRARY)
+  set(PYTHON_DEBUG_LIBRARY "")
+endif()
+set(PYTHON_DEBUG_LIBRARIES "${PYTHON_DEBUG_LIBRARY}")
+
+find_package_message(PYTHON "Found PythonLibs: ${PYTHON_LIBRARY}"
+                     "${PYTHON_EXECUTABLE}${PYTHON_VERSION_STRING}")
+
+set(PYTHONLIBS_FOUND TRUE)
+set(PythonLibsNew_FOUND TRUE)
+
+if(NOT PYTHON_MODULE_PREFIX)
+  set(PYTHON_MODULE_PREFIX "")
+endif()

third-party/DPVO/DPViewer/pybind11/tools/check-style.sh

@@ -0,0 +1,44 @@
+#!/bin/bash
+#
+# Script to check include/test code for common pybind11 code style errors.
+#
+# This script currently checks for
+#
+# 1. missing space between keyword and parenthesis, e.g.: for(, if(, while(
+# 2. Missing space between right parenthesis and brace, e.g. 'for (...){'
+# 3. opening brace on its own line. It should always be on the same line as the
+#    if/while/for/do statement.
+#
+# Invoke as: tools/check-style.sh <filenames>
+#
+
+check_style_errors=0
+IFS=$'\n'
+
+
+found="$(grep '\<\(if\|for\|while\|catch\)(\|){' "$@" -rn --color=always)"
+if [ -n "$found" ]; then
+    echo -e '\033[31;01mError: found the following coding style problems:\033[0m'
+    check_style_errors=1
+    echo "${found//^/    /}"
+fi
+
+found="$(awk '
+function prefix(filename, lineno) {
+    return "    \033[35m" filename "\033[36m:\033[32m" lineno "\033[36m:\033[0m"
+}
+function mark(pattern, string) { sub(pattern, "\033[01;31m&\033[0m", string); return string }
+last && /^\s*{/ {
+    print prefix(FILENAME, FNR-1) mark("\\)\\s*$", last)
+    print prefix(FILENAME, FNR)   mark("^\\s*{", $0)
+    last=""
+}
+{ last = /(if|for|while|catch|switch)\s*\(.*\)\s*$/ ? $0 : "" }
+' "$(find include -type f)" "$@")"
+if [ -n "$found" ]; then
+    check_style_errors=1
+    echo -e '\033[31;01mError: braces should occur on the same line as the if/while/.. statement. Found issues in the following files:\033[0m'
+    echo "$found"
+fi
+
+exit $check_style_errors

third-party/DPVO/DPViewer/pybind11/tools/cmake_uninstall.cmake.in

@@ -0,0 +1,23 @@
+# Source: https://gitlab.kitware.com/cmake/community/-/wikis/FAQ#can-i-do-make-uninstall-with-cmake
+
+if(NOT EXISTS "@CMAKE_BINARY_DIR@/install_manifest.txt")
+  message(FATAL_ERROR "Cannot find install manifest: @CMAKE_BINARY_DIR@/install_manifest.txt")
+endif()
+
+file(READ "@CMAKE_BINARY_DIR@/install_manifest.txt" files)
+string(REGEX REPLACE "\n" ";" files "${files}")
+foreach(file ${files})
+  message(STATUS "Uninstalling $ENV{DESTDIR}${file}")
+  if(IS_SYMLINK "$ENV{DESTDIR}${file}" OR EXISTS "$ENV{DESTDIR}${file}")
+    exec_program(
+      "@CMAKE_COMMAND@" ARGS
+      "-E remove \"$ENV{DESTDIR}${file}\""
+      OUTPUT_VARIABLE rm_out
+      RETURN_VALUE rm_retval)
+    if(NOT "${rm_retval}" STREQUAL 0)
+      message(FATAL_ERROR "Problem when removing $ENV{DESTDIR}${file}")
+    endif()
+  else(IS_SYMLINK "$ENV{DESTDIR}${file}" OR EXISTS "$ENV{DESTDIR}${file}")
+    message(STATUS "File $ENV{DESTDIR}${file} does not exist.")
+  endif()
+endforeach()

third-party/DPVO/DPViewer/pybind11/tools/libsize.py

@@ -0,0 +1,36 @@
+import os
+import sys
+
+# Internal build script for generating debugging test .so size.
+# Usage:
+#     python libsize.py file.so save.txt -- displays the size of file.so and, if save.txt exists, compares it to the
+#                                           size in it, then overwrites save.txt with the new size for future runs.
+
+if len(sys.argv) != 3:
+    sys.exit("Invalid arguments: usage: python libsize.py file.so save.txt")
+
+lib = sys.argv[1]
+save = sys.argv[2]
+
+if not os.path.exists(lib):
+    sys.exit(f"Error: requested file ({lib}) does not exist")
+
+libsize = os.path.getsize(lib)
+
+print("------", os.path.basename(lib), "file size:", libsize, end="")
+
+if os.path.exists(save):
+    with open(save) as sf:
+        oldsize = int(sf.readline())
+
+    if oldsize > 0:
+        change = libsize - oldsize
+        if change == 0:
+            print(" (no change)")
+        else:
+            print(f" (change of {change:+} bytes = {change / oldsize:+.2%})")
+else:
+    print()
+
+with open(save, "w") as sf:
+    sf.write(str(libsize))

third-party/DPVO/DPViewer/pybind11/tools/make_changelog.py

@@ -0,0 +1,63 @@
+#!/usr/bin/env python3
+
+import re
+
+import ghapi.all
+from rich import print
+from rich.syntax import Syntax
+
+ENTRY = re.compile(
+    r"""
+    Suggested \s changelog \s entry:
+    .*
+    ```rst
+    \s*
+    (.*?)
+    \s*
+    ```
+""",
+    re.DOTALL | re.VERBOSE,
+)
+
+print()
+
+
+api = ghapi.all.GhApi(owner="pybind", repo="pybind11")
+
+issues_pages = ghapi.page.paged(
+    api.issues.list_for_repo, labels="needs changelog", state="closed"
+)
+issues = (issue for page in issues_pages for issue in page)
+missing = []
+
+for issue in issues:
+    changelog = ENTRY.findall(issue.body)
+    if changelog:
+        (msg,) = changelog
+        if not msg.startswith("* "):
+            msg = "* " + msg
+        if not msg.endswith("."):
+            msg += "."
+
+        msg += f"\n  `#{issue.number} <{issue.html_url}>`_"
+
+        print(Syntax(msg, "rst", theme="ansi_light", word_wrap=True))
+        print()
+
+    else:
+        missing.append(issue)
+
+if missing:
+    print()
+    print("[blue]" + "-" * 30)
+    print()
+
+    for issue in missing:
+        print(f"[red bold]Missing:[/red bold][red] {issue.title}")
+        print(f"[red]  {issue.html_url}\n")
+
+    print("[bold]Template:\n")
+    msg = "## Suggested changelog entry:\n\n```rst\n\n```"
+    print(Syntax(msg, "md", theme="ansi_light"))
+
+print()

third-party/DPVO/DPViewer/pybind11/tools/pybind11Common.cmake

@@ -0,0 +1,385 @@
+#[======================================================[.rst
+
+Adds the following targets::
+
+    pybind11::pybind11 - link to headers and pybind11
+    pybind11::module - Adds module links
+    pybind11::embed - Adds embed links
+    pybind11::lto - Link time optimizations (manual selection)
+    pybind11::thin_lto - Link time optimizations (manual selection)
+    pybind11::python_link_helper - Adds link to Python libraries
+    pybind11::windows_extras - MSVC bigobj and mp for building multithreaded
+    pybind11::opt_size - avoid optimizations that increase code size
+
+Adds the following functions::
+
+    pybind11_strip(target) - strip target after building on linux/macOS
+    pybind11_find_import(module) - See if a module is installed.
+
+#]======================================================]
+
+# CMake 3.10 has an include_guard command, but we can't use that yet
+# include_guard(global) (pre-CMake 3.10)
+if(TARGET pybind11::lto)
+  return()
+endif()
+
+# If we are in subdirectory mode, all IMPORTED targets must be GLOBAL. If we
+# are in CONFIG mode, they should be "normal" targets instead.
+# In CMake 3.11+ you can promote a target to global after you create it,
+# which might be simpler than this check.
+get_property(
+  is_config
+  TARGET pybind11::headers
+  PROPERTY IMPORTED)
+if(NOT is_config)
+  set(optional_global GLOBAL)
+endif()
+
+# If not run in Python mode, we still would like this to at least
+# include pybind11's include directory:
+set(pybind11_INCLUDE_DIRS
+    "${pybind11_INCLUDE_DIR}"
+    CACHE INTERNAL "Include directory for pybind11 (Python not requested)")
+
+# --------------------- Shared targets ----------------------------
+
+# Build an interface library target:
+add_library(pybind11::pybind11 IMPORTED INTERFACE ${optional_global})
+set_property(
+  TARGET pybind11::pybind11
+  APPEND
+  PROPERTY INTERFACE_LINK_LIBRARIES pybind11::headers)
+
+# Build a module target:
+add_library(pybind11::module IMPORTED INTERFACE ${optional_global})
+set_property(
+  TARGET pybind11::module
+  APPEND
+  PROPERTY INTERFACE_LINK_LIBRARIES pybind11::pybind11)
+
+# Build an embed library target:
+add_library(pybind11::embed IMPORTED INTERFACE ${optional_global})
+set_property(
+  TARGET pybind11::embed
+  APPEND
+  PROPERTY INTERFACE_LINK_LIBRARIES pybind11::pybind11)
+
+# --------------------------- link helper ---------------------------
+
+add_library(pybind11::python_link_helper IMPORTED INTERFACE ${optional_global})
+
+if(CMAKE_VERSION VERSION_LESS 3.13)
+  # In CMake 3.11+, you can set INTERFACE properties via the normal methods, and
+  # this would be simpler.
+  set_property(
+    TARGET pybind11::python_link_helper
+    APPEND
+    PROPERTY INTERFACE_LINK_LIBRARIES "$<$<PLATFORM_ID:Darwin>:-undefined dynamic_lookup>")
+else()
+  # link_options was added in 3.13+
+  # This is safer, because you are ensured the deduplication pass in CMake will not consider
+  # these separate and remove one but not the other.
+  set_property(
+    TARGET pybind11::python_link_helper
+    APPEND
+    PROPERTY INTERFACE_LINK_OPTIONS "$<$<PLATFORM_ID:Darwin>:LINKER:-undefined,dynamic_lookup>")
+endif()
+
+# ------------------------ Windows extras -------------------------
+
+add_library(pybind11::windows_extras IMPORTED INTERFACE ${optional_global})
+
+if(MSVC) # That's also clang-cl
+  # /bigobj is needed for bigger binding projects due to the limit to 64k
+  # addressable sections
+  set_property(
+    TARGET pybind11::windows_extras
+    APPEND
+    PROPERTY INTERFACE_COMPILE_OPTIONS $<$<COMPILE_LANGUAGE:CXX>:/bigobj>)
+
+  # /MP enables multithreaded builds (relevant when there are many files) for MSVC
+  if("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC") # no Clang no Intel
+    if(CMAKE_VERSION VERSION_LESS 3.11)
+      set_property(
+        TARGET pybind11::windows_extras
+        APPEND
+        PROPERTY INTERFACE_COMPILE_OPTIONS $<$<NOT:$<CONFIG:Debug>>:/MP>)
+    else()
+      # Only set these options for C++ files.  This is important so that, for
+      # instance, projects that include other types of source files like CUDA
+      # .cu files don't get these options propagated to nvcc since that would
+      # cause the build to fail.
+      set_property(
+        TARGET pybind11::windows_extras
+        APPEND
+        PROPERTY INTERFACE_COMPILE_OPTIONS
+                 $<$<NOT:$<CONFIG:Debug>>:$<$<COMPILE_LANGUAGE:CXX>:/MP>>)
+    endif()
+  endif()
+endif()
+
+# ----------------------- Optimize binary size --------------------------
+
+add_library(pybind11::opt_size IMPORTED INTERFACE ${optional_global})
+
+if(MSVC)
+  set(PYBIND11_OPT_SIZE /Os)
+else()
+  set(PYBIND11_OPT_SIZE -Os)
+endif()
+
+set_property(
+  TARGET pybind11::opt_size
+  APPEND
+  PROPERTY INTERFACE_COMPILE_OPTIONS $<$<CONFIG:Release>:${PYBIND11_OPT_SIZE}>
+           $<$<CONFIG:MinSizeRel>:${PYBIND11_OPT_SIZE}>
+           $<$<CONFIG:RelWithDebInfo>:${PYBIND11_OPT_SIZE}>)
+
+# ----------------------- Legacy option --------------------------
+
+# Warn or error if old variable name used
+if(PYBIND11_CPP_STANDARD)
+  string(REGEX MATCH [[..$]] VAL "${PYBIND11_CPP_STANDARD}")
+  if(CMAKE_CXX_STANDARD)
+    if(NOT CMAKE_CXX_STANDARD STREQUAL VAL)
+      message(WARNING "CMAKE_CXX_STANDARD=${CMAKE_CXX_STANDARD} does not match "
+                      "PYBIND11_CPP_STANDARD=${PYBIND11_CPP_STANDARD}, "
+                      "please remove PYBIND11_CPP_STANDARD from your cache")
+    endif()
+  else()
+    set(supported_standards 11 14 17 20)
+    if("${VAL}" IN_LIST supported_standards)
+      message(WARNING "USE -DCMAKE_CXX_STANDARD=${VAL} instead of PYBIND11_CPP_STANDARD")
+      set(CMAKE_CXX_STANDARD
+          ${VAL}
+          CACHE STRING "From PYBIND11_CPP_STANDARD")
+    else()
+      message(FATAL_ERROR "PYBIND11_CPP_STANDARD should be replaced with CMAKE_CXX_STANDARD "
+                          "(last two chars: ${VAL} not understood as a valid CXX std)")
+    endif()
+  endif()
+endif()
+
+# --------------------- Python specifics -------------------------
+
+# Check to see which Python mode we are in, new, old, or no python
+if(PYBIND11_NOPYTHON)
+  set(_pybind11_nopython ON)
+elseif(
+  PYBIND11_FINDPYTHON
+  OR Python_FOUND
+  OR Python2_FOUND
+  OR Python3_FOUND)
+  # New mode
+  include("${CMAKE_CURRENT_LIST_DIR}/pybind11NewTools.cmake")
+
+else()
+
+  # Classic mode
+  include("${CMAKE_CURRENT_LIST_DIR}/pybind11Tools.cmake")
+
+endif()
+
+# --------------------- pybind11_find_import -------------------------------
+
+if(NOT _pybind11_nopython)
+  # Check to see if modules are importable. Use REQUIRED to force an error if
+  # one of the modules is not found. <package_name>_FOUND will be set if the
+  # package was found (underscores replace dashes if present). QUIET will hide
+  # the found message, and VERSION will require a minimum version. A successful
+  # find will cache the result.
+  function(pybind11_find_import PYPI_NAME)
+    # CMake variables need underscores (PyPI doesn't care)
+    string(REPLACE "-" "_" NORM_PYPI_NAME "${PYPI_NAME}")
+
+    # Return if found previously
+    if(${NORM_PYPI_NAME}_FOUND)
+      return()
+    endif()
+
+    set(options "REQUIRED;QUIET")
+    set(oneValueArgs "VERSION")
+    cmake_parse_arguments(ARG "${options}" "${oneValueArgs}" "" ${ARGN})
+
+    if(ARG_REQUIRED)
+      set(status_level FATAL_ERROR)
+    else()
+      set(status_level WARNING)
+    endif()
+
+    execute_process(
+      COMMAND
+        ${${_Python}_EXECUTABLE} -c
+        "from pkg_resources import get_distribution; print(get_distribution('${PYPI_NAME}').version)"
+      RESULT_VARIABLE RESULT_PRESENT
+      OUTPUT_VARIABLE PKG_VERSION
+      ERROR_QUIET)
+
+    string(STRIP "${PKG_VERSION}" PKG_VERSION)
+
+    # If a result is present, this failed
+    if(RESULT_PRESENT)
+      set(${NORM_PYPI_NAME}_FOUND
+          ${NORM_PYPI_NAME}-NOTFOUND
+          CACHE INTERNAL "")
+      # Always warn or error
+      message(
+        ${status_level}
+        "Missing: ${PYPI_NAME} ${ARG_VERSION}\nTry: ${${_Python}_EXECUTABLE} -m pip install ${PYPI_NAME}"
+      )
+    else()
+      if(ARG_VERSION AND PKG_VERSION VERSION_LESS ARG_VERSION)
+        message(
+          ${status_level}
+          "Version incorrect: ${PYPI_NAME} ${PKG_VERSION} found, ${ARG_VERSION} required - try upgrading"
+        )
+      else()
+        set(${NORM_PYPI_NAME}_FOUND
+            YES
+            CACHE INTERNAL "")
+        set(${NORM_PYPI_NAME}_VERSION
+            ${PKG_VERSION}
+            CACHE INTERNAL "")
+      endif()
+      if(NOT ARG_QUIET)
+        message(STATUS "Found ${PYPI_NAME} ${PKG_VERSION}")
+      endif()
+    endif()
+    if(NOT ARG_VERSION OR (NOT PKG_VERSION VERSION_LESS ARG_VERSION))
+      # We have successfully found a good version, cache to avoid calling again.
+    endif()
+  endfunction()
+endif()
+
+# --------------------- LTO -------------------------------
+
+include(CheckCXXCompilerFlag)
+
+# Checks whether the given CXX/linker flags can compile and link a cxx file.
+# cxxflags and linkerflags are lists of flags to use.  The result variable is a
+# unique variable name for each set of flags: the compilation result will be
+# cached base on the result variable.  If the flags work, sets them in
+# cxxflags_out/linkerflags_out internal cache variables (in addition to
+# ${result}).
+function(_pybind11_return_if_cxx_and_linker_flags_work result cxxflags linkerflags cxxflags_out
+         linkerflags_out)
+  set(CMAKE_REQUIRED_LIBRARIES ${linkerflags})
+  check_cxx_compiler_flag("${cxxflags}" ${result})
+  if(${result})
+    set(${cxxflags_out}
+        "${cxxflags}"
+        PARENT_SCOPE)
+    set(${linkerflags_out}
+        "${linkerflags}"
+        PARENT_SCOPE)
+  endif()
+endfunction()
+
+function(_pybind11_generate_lto target prefer_thin_lto)
+  if(MINGW)
+    message(STATUS "${target} disabled (problems with undefined symbols for MinGW for now)")
+    return()
+  endif()
+
+  if(CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
+    set(cxx_append "")
+    set(linker_append "")
+    if(CMAKE_CXX_COMPILER_ID MATCHES "Clang" AND NOT APPLE)
+      # Clang Gold plugin does not support -Os; append -O3 to MinSizeRel builds to override it
+      set(linker_append ";$<$<CONFIG:MinSizeRel>:-O3>")
+    elseif(CMAKE_CXX_COMPILER_ID MATCHES "GNU" AND NOT MINGW)
+      set(cxx_append ";-fno-fat-lto-objects")
+    endif()
+
+    if(CMAKE_SYSTEM_PROCESSOR MATCHES "ppc64le" OR CMAKE_SYSTEM_PROCESSOR MATCHES "mips64")
+      set(NO_FLTO_ARCH TRUE)
+    else()
+      set(NO_FLTO_ARCH FALSE)
+    endif()
+
+    if(CMAKE_CXX_COMPILER_ID MATCHES "Clang"
+       AND prefer_thin_lto
+       AND NOT NO_FLTO_ARCH)
+      _pybind11_return_if_cxx_and_linker_flags_work(
+        HAS_FLTO_THIN "-flto=thin${cxx_append}" "-flto=thin${linker_append}"
+        PYBIND11_LTO_CXX_FLAGS PYBIND11_LTO_LINKER_FLAGS)
+    endif()
+
+    if(NOT HAS_FLTO_THIN AND NOT NO_FLTO_ARCH)
+      _pybind11_return_if_cxx_and_linker_flags_work(
+        HAS_FLTO "-flto${cxx_append}" "-flto${linker_append}" PYBIND11_LTO_CXX_FLAGS
+        PYBIND11_LTO_LINKER_FLAGS)
+    endif()
+  elseif(CMAKE_CXX_COMPILER_ID MATCHES "Intel")
+    # Intel equivalent to LTO is called IPO
+    _pybind11_return_if_cxx_and_linker_flags_work(HAS_INTEL_IPO "-ipo" "-ipo"
+                                                  PYBIND11_LTO_CXX_FLAGS PYBIND11_LTO_LINKER_FLAGS)
+  elseif(MSVC)
+    # cmake only interprets libraries as linker flags when they start with a - (otherwise it
+    # converts /LTCG to \LTCG as if it was a Windows path).  Luckily MSVC supports passing flags
+    # with - instead of /, even if it is a bit non-standard:
+    _pybind11_return_if_cxx_and_linker_flags_work(HAS_MSVC_GL_LTCG "/GL" "-LTCG"
+                                                  PYBIND11_LTO_CXX_FLAGS PYBIND11_LTO_LINKER_FLAGS)
+  endif()
+
+  # Enable LTO flags if found, except for Debug builds
+  if(PYBIND11_LTO_CXX_FLAGS)
+    # CONFIG takes multiple values in CMake 3.19+, until then we have to use OR
+    set(is_debug "$<OR:$<CONFIG:Debug>,$<CONFIG:RelWithDebInfo>>")
+    set(not_debug "$<NOT:${is_debug}>")
+    set(cxx_lang "$<COMPILE_LANGUAGE:CXX>")
+    if(MSVC AND CMAKE_VERSION VERSION_LESS 3.11)
+      set(genex "${not_debug}")
+    else()
+      set(genex "$<AND:${not_debug},${cxx_lang}>")
+    endif()
+    set_property(
+      TARGET ${target}
+      APPEND
+      PROPERTY INTERFACE_COMPILE_OPTIONS "$<${genex}:${PYBIND11_LTO_CXX_FLAGS}>")
+    if(CMAKE_PROJECT_NAME STREQUAL "pybind11")
+      message(STATUS "${target} enabled")
+    endif()
+  else()
+    if(CMAKE_PROJECT_NAME STREQUAL "pybind11")
+      message(STATUS "${target} disabled (not supported by the compiler and/or linker)")
+    endif()
+  endif()
+
+  if(PYBIND11_LTO_LINKER_FLAGS)
+    if(CMAKE_VERSION VERSION_LESS 3.11)
+      set_property(
+        TARGET ${target}
+        APPEND
+        PROPERTY INTERFACE_LINK_LIBRARIES "$<${not_debug}:${PYBIND11_LTO_LINKER_FLAGS}>")
+    else()
+      set_property(
+        TARGET ${target}
+        APPEND
+        PROPERTY INTERFACE_LINK_OPTIONS "$<${not_debug}:${PYBIND11_LTO_LINKER_FLAGS}>")
+    endif()
+  endif()
+endfunction()
+
+add_library(pybind11::lto IMPORTED INTERFACE ${optional_global})
+_pybind11_generate_lto(pybind11::lto FALSE)
+
+add_library(pybind11::thin_lto IMPORTED INTERFACE ${optional_global})
+_pybind11_generate_lto(pybind11::thin_lto TRUE)
+
+# ---------------------- pybind11_strip -----------------------------
+
+function(pybind11_strip target_name)
+  # Strip unnecessary sections of the binary on Linux/macOS
+  if(CMAKE_STRIP)
+    if(APPLE)
+      set(x_opt -x)
+    endif()
+
+    add_custom_command(
+      TARGET ${target_name}
+      POST_BUILD
+      COMMAND ${CMAKE_STRIP} ${x_opt} $<TARGET_FILE:${target_name}>)
+  endif()
+endfunction()

third-party/DPVO/DPViewer/pybind11/tools/pybind11Config.cmake.in

@@ -0,0 +1,231 @@
+#[=============================================================================[.rst:
+
+pybind11Config.cmake
+####################
+
+Exported variables
+==================
+
+This module sets the following variables in your project:
+
+``pybind11_FOUND``
+  true if pybind11 and all required components found on the system
+``pybind11_VERSION``
+  pybind11 version in format Major.Minor.Release
+``pybind11_VERSION_TYPE``
+  pybind11 version type (``dev*`` or empty for a release)
+``pybind11_INCLUDE_DIRS``
+  Directories where pybind11 and python headers are located.
+``pybind11_INCLUDE_DIR``
+  Directory where pybind11 headers are located.
+``pybind11_DEFINITIONS``
+  Definitions necessary to use pybind11, namely USING_pybind11.
+``pybind11_LIBRARIES``
+  Compile flags and python libraries (as needed) to link against.
+``pybind11_LIBRARY``
+  Empty.
+
+Available components: None
+
+
+Exported targets
+================
+
+If pybind11 is found, this module defines the following ``IMPORTED``
+interface library targets:
+
+``pybind11::module``
+  for extension modules.
+``pybind11::embed``
+  for embedding the Python interpreter.
+
+Python headers, libraries (as needed by platform), and the C++ standard
+are attached to the target.
+
+Advanced targets are also supplied - these are primary for users building
+complex applications, and they are available in all modes:
+
+``pybind11::headers``
+  Just the pybind11 headers and minimum compile requirements.
+``pybind11::pybind11``
+  Python headers too.
+``pybind11::python_link_helper``
+  Just the "linking" part of ``pybind11:module``, for CMake < 3.15.
+``pybind11::thin_lto``
+  An alternative to ``INTERPROCEDURAL_OPTIMIZATION``.
+``pybind11::lto``
+  An alternative to ``INTERPROCEDURAL_OPTIMIZATION`` (also avoids thin LTO on clang).
+``pybind11::windows_extras``
+  Adds bigobj and mp for MSVC.
+
+Modes
+=====
+
+There are two modes provided; classic, which is built on the old Python
+discovery packages in CMake, or the new FindPython mode, which uses FindPython
+from 3.12+ forward (3.15+ _highly_ recommended).
+
+New FindPython mode
+^^^^^^^^^^^^^^^^^^^
+
+To activate this mode, either call ``find_package(Python COMPONENTS Interpreter Development)``
+before finding this package, or set the ``PYBIND11_FINDPYTHON`` variable to ON. In this mode,
+you can either use the basic targets, or use the FindPython tools:
+
+.. code-block:: cmake
+
+  find_package(Python COMPONENTS Interpreter Development)
+  find_package(pybind11 CONFIG)
+
+  # pybind11 method:
+  pybind11_add_module(MyModule1 src1.cpp)
+
+  # Python method:
+  Python_add_library(MyModule2 src2.cpp)
+  target_link_libraries(MyModule2 pybind11::headers)
+  set_target_properties(MyModule2 PROPERTIES
+                                  INTERPROCEDURAL_OPTIMIZATION ON
+                                  CXX_VISIBILITY_PRESET ON
+                                  VISIBILITY_INLINES_HIDDEN ON)
+
+If you build targets yourself, you may be interested in stripping the output
+for reduced size; this is the one other feature that the helper function gives you.
+
+Classic mode
+^^^^^^^^^^^^
+
+Set PythonLibsNew variables to influence python detection and
+CMAKE_CXX_STANDARD to influence standard setting.
+
+.. code-block:: cmake
+
+  find_package(pybind11 CONFIG REQUIRED)
+
+  # Create an extension module
+  add_library(mylib MODULE main.cpp)
+  target_link_libraries(mylib PUBLIC pybind11::module)
+
+  # Or embed the Python interpreter into an executable
+  add_executable(myexe main.cpp)
+  target_link_libraries(myexe PUBLIC pybind11::embed)
+
+
+Hints
+=====
+
+The following variables can be set to guide the search for this package:
+
+``pybind11_DIR``
+  CMake variable, set to directory containing this Config file.
+``CMAKE_PREFIX_PATH``
+  CMake variable, set to root directory of this package.
+``PATH``
+  Environment variable, set to bin directory of this package.
+``CMAKE_DISABLE_FIND_PACKAGE_pybind11``
+  CMake variable, disables ``find_package(pybind11)`` when not ``REQUIRED``,
+  perhaps to force internal build.
+
+Commands
+========
+
+pybind11_add_module
+^^^^^^^^^^^^^^^^^^^
+
+This module defines the following commands to assist with creating Python modules:
+
+.. code-block:: cmake
+
+  pybind11_add_module(<target>
+    [STATIC|SHARED|MODULE]
+    [THIN_LTO] [OPT_SIZE] [NO_EXTRAS] [WITHOUT_SOABI]
+    <files>...
+    )
+
+Add a module and setup all helpers. You can select the type of the library; the
+default is ``MODULE``. There are several options:
+
+``OPT_SIZE``
+  Optimize for size, even if the ``CMAKE_BUILD_TYPE`` is not ``MinSizeRel``.
+``THIN_LTO``
+  Use thin TLO instead of regular if there's a choice (pybind11's selection
+  is disabled if ``CMAKE_INTERPROCEDURAL_OPTIMIZATIONS`` is set).
+``WITHOUT_SOABI``
+  Disable the SOABI component (``PYBIND11_NEWPYTHON`` mode only).
+``NO_EXTRAS``
+  Disable all extras, exit immediately after making the module.
+
+pybind11_strip
+^^^^^^^^^^^^^^
+
+.. code-block:: cmake
+
+  pybind11_strip(<target>)
+
+Strip a target after building it (linux/macOS), called by ``pybind11_add_module``.
+
+pybind11_extension
+^^^^^^^^^^^^^^^^^^
+
+.. code-block:: cmake
+
+    pybind11_extension(<target>)
+
+Sets the Python extension name correctly for Python on your platform, called by
+``pybind11_add_module``.
+
+pybind11_find_import(module)
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+.. code-block:: cmake
+
+    pybind11_find_import(<module> [VERSION <number>] [REQUIRED] [QUIET])
+
+See if a module is installed. Use the registered name (the one on PyPI). You
+can specify a ``VERSION``, and you can specify ``REQUIRED`` or ``QUIET``. Only available if
+``NOPYTHON`` mode is not active.  Sets ``module_VERSION`` and ``module_FOUND``. Caches the
+result once a valid install is found.
+
+Suggested usage
+===============
+
+Using ``find_package`` with version info is not recommended except for release versions.
+
+.. code-block:: cmake
+
+  find_package(pybind11 CONFIG)
+  find_package(pybind11 2.9 EXACT CONFIG REQUIRED)
+
+#]=============================================================================]
+@PACKAGE_INIT@
+
+# Location of pybind11/pybind11.h
+# This will be relative unless explicitly set as absolute
+set(pybind11_INCLUDE_DIR "@pybind11_INCLUDEDIR@")
+
+set(pybind11_LIBRARY "")
+set(pybind11_DEFINITIONS USING_pybind11)
+set(pybind11_VERSION_TYPE "@pybind11_VERSION_TYPE@")
+
+check_required_components(pybind11)
+
+if(TARGET pybind11::python_link_helper)
+  # This has already been setup elsewhere, such as with a previous call or
+  # add_subdirectory
+  return()
+endif()
+
+include("${CMAKE_CURRENT_LIST_DIR}/pybind11Targets.cmake")
+
+# Easier to use / remember
+add_library(pybind11::headers IMPORTED INTERFACE)
+set_target_properties(pybind11::headers PROPERTIES INTERFACE_LINK_LIBRARIES
+                                                   pybind11::pybind11_headers)
+
+include("${CMAKE_CURRENT_LIST_DIR}/pybind11Common.cmake")
+
+if(NOT pybind11_FIND_QUIETLY)
+  message(
+    STATUS
+      "Found pybind11: ${pybind11_INCLUDE_DIR} (found version \"${pybind11_VERSION}${pybind11_VERSION_TYPE}\")"
+  )
+endif()

third-party/DPVO/DPViewer/pybind11/tools/pybind11NewTools.cmake

@@ -0,0 +1,254 @@
+# tools/pybind11NewTools.cmake -- Build system for the pybind11 modules
+#
+# Copyright (c) 2020 Wenzel Jakob <[email protected]> and Henry Schreiner
+#
+# All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+if(CMAKE_VERSION VERSION_LESS 3.12)
+  message(FATAL_ERROR "You cannot use the new FindPython module with CMake < 3.12")
+endif()
+
+include_guard(GLOBAL)
+
+get_property(
+  is_config
+  TARGET pybind11::headers
+  PROPERTY IMPORTED)
+
+if(pybind11_FIND_QUIETLY)
+  set(_pybind11_quiet QUIET)
+else()
+  set(_pybind11_quiet "")
+endif()
+
+if(NOT Python_FOUND AND NOT Python3_FOUND)
+  if(NOT DEFINED Python_FIND_IMPLEMENTATIONS)
+    set(Python_FIND_IMPLEMENTATIONS CPython PyPy)
+  endif()
+
+  # GitHub Actions like activation
+  if(NOT DEFINED Python_ROOT_DIR AND DEFINED ENV{pythonLocation})
+    set(Python_ROOT_DIR "$ENV{pythonLocation}")
+  endif()
+
+  find_package(Python 3.6 REQUIRED COMPONENTS Interpreter Development ${_pybind11_quiet})
+
+  # If we are in submodule mode, export the Python targets to global targets.
+  # If this behavior is not desired, FindPython _before_ pybind11.
+  if(NOT is_config)
+    set_property(TARGET Python::Python PROPERTY IMPORTED_GLOBAL TRUE)
+    set_property(TARGET Python::Interpreter PROPERTY IMPORTED_GLOBAL TRUE)
+    if(TARGET Python::Module)
+      set_property(TARGET Python::Module PROPERTY IMPORTED_GLOBAL TRUE)
+    endif()
+  endif()
+endif()
+
+if(Python_FOUND)
+  set(_Python
+      Python
+      CACHE INTERNAL "" FORCE)
+elseif(Python3_FOUND)
+  set(_Python
+      Python3
+      CACHE INTERNAL "" FORCE)
+endif()
+
+if(PYBIND11_MASTER_PROJECT)
+  if(${_Python}_INTERPRETER_ID MATCHES "PyPy")
+    message(STATUS "PyPy ${${_Python}_PyPy_VERSION} (Py ${${_Python}_VERSION})")
+  else()
+    message(STATUS "${_Python} ${${_Python}_VERSION}")
+  endif()
+endif()
+
+# If a user finds Python, they may forget to include the Interpreter component
+# and the following two steps require it. It is highly recommended by CMake
+# when finding development libraries anyway, so we will require it.
+if(NOT DEFINED ${_Python}_EXECUTABLE)
+  message(
+    FATAL_ERROR
+      "${_Python} was found without the Interpreter component. Pybind11 requires this component.")
+
+endif()
+
+if(NOT ${_Python}_EXECUTABLE STREQUAL PYBIND11_PYTHON_EXECUTABLE_LAST)
+  # Detect changes to the Python version/binary in subsequent CMake runs, and refresh config if needed
+  unset(PYTHON_IS_DEBUG CACHE)
+  unset(PYTHON_MODULE_EXTENSION CACHE)
+  set(PYBIND11_PYTHON_EXECUTABLE_LAST
+      "${${_Python}_EXECUTABLE}"
+      CACHE INTERNAL "Python executable during the last CMake run")
+endif()
+
+if(NOT DEFINED PYTHON_IS_DEBUG)
+  # Debug check - see https://stackoverflow.com/questions/646518/python-how-to-detect-debug-Interpreter
+  execute_process(
+    COMMAND "${${_Python}_EXECUTABLE}" "-c"
+            "import sys; sys.exit(hasattr(sys, 'gettotalrefcount'))"
+    RESULT_VARIABLE _PYTHON_IS_DEBUG)
+  set(PYTHON_IS_DEBUG
+      "${_PYTHON_IS_DEBUG}"
+      CACHE INTERNAL "Python debug status")
+endif()
+
+# Get the suffix - SO is deprecated, should use EXT_SUFFIX, but this is
+# required for PyPy3 (as of 7.3.1)
+if(NOT DEFINED PYTHON_MODULE_EXTENSION)
+  execute_process(
+    COMMAND
+      "${${_Python}_EXECUTABLE}" "-c"
+      "import sys, importlib; s = importlib.import_module('distutils.sysconfig' if sys.version_info < (3, 10) else 'sysconfig'); print(s.get_config_var('EXT_SUFFIX') or s.get_config_var('SO'))"
+    OUTPUT_VARIABLE _PYTHON_MODULE_EXTENSION
+    ERROR_VARIABLE _PYTHON_MODULE_EXTENSION_ERR
+    OUTPUT_STRIP_TRAILING_WHITESPACE)
+
+  if(_PYTHON_MODULE_EXTENSION STREQUAL "")
+    message(
+      FATAL_ERROR "pybind11 could not query the module file extension, likely the 'distutils'"
+                  "package is not installed. Full error message:\n${_PYTHON_MODULE_EXTENSION_ERR}")
+  endif()
+
+  # This needs to be available for the pybind11_extension function
+  set(PYTHON_MODULE_EXTENSION
+      "${_PYTHON_MODULE_EXTENSION}"
+      CACHE INTERNAL "")
+endif()
+
+# Python debug libraries expose slightly different objects before 3.8
+# https://docs.python.org/3.6/c-api/intro.html#debugging-builds
+# https://stackoverflow.com/questions/39161202/how-to-work-around-missing-pymodule-create2-in-amd64-win-python35-d-lib
+if(PYTHON_IS_DEBUG)
+  set_property(
+    TARGET pybind11::pybind11
+    APPEND
+    PROPERTY INTERFACE_COMPILE_DEFINITIONS Py_DEBUG)
+endif()
+
+# Check on every access - since Python can change - do nothing in that case.
+
+if(DEFINED ${_Python}_INCLUDE_DIRS)
+  # Only add Python for build - must be added during the import for config
+  # since it has to be re-discovered.
+  #
+  # This needs to be a target to be included after the local pybind11
+  # directory, just in case there there is an installed pybind11 sitting
+  # next to Python's includes. It also ensures Python is a SYSTEM library.
+  add_library(pybind11::python_headers INTERFACE IMPORTED)
+  set_property(
+    TARGET pybind11::python_headers PROPERTY INTERFACE_INCLUDE_DIRECTORIES
+                                             "$<BUILD_INTERFACE:${${_Python}_INCLUDE_DIRS}>")
+  set_property(
+    TARGET pybind11::pybind11
+    APPEND
+    PROPERTY INTERFACE_LINK_LIBRARIES pybind11::python_headers)
+  set(pybind11_INCLUDE_DIRS
+      "${pybind11_INCLUDE_DIR}" "${${_Python}_INCLUDE_DIRS}"
+      CACHE INTERNAL "Directories where pybind11 and possibly Python headers are located")
+endif()
+
+# In CMake 3.18+, you can find these separately, so include an if
+if(TARGET ${_Python}::Python)
+  set_property(
+    TARGET pybind11::embed
+    APPEND
+    PROPERTY INTERFACE_LINK_LIBRARIES ${_Python}::Python)
+endif()
+
+# CMake 3.15+ has this
+if(TARGET ${_Python}::Module)
+  set_property(
+    TARGET pybind11::module
+    APPEND
+    PROPERTY INTERFACE_LINK_LIBRARIES ${_Python}::Module)
+else()
+  set_property(
+    TARGET pybind11::module
+    APPEND
+    PROPERTY INTERFACE_LINK_LIBRARIES pybind11::python_link_helper)
+endif()
+
+# WITHOUT_SOABI and WITH_SOABI will disable the custom extension handling used by pybind11.
+# WITH_SOABI is passed on to python_add_library.
+function(pybind11_add_module target_name)
+  cmake_parse_arguments(PARSE_ARGV 1 ARG
+                        "STATIC;SHARED;MODULE;THIN_LTO;OPT_SIZE;NO_EXTRAS;WITHOUT_SOABI" "" "")
+
+  if(ARG_STATIC)
+    set(lib_type STATIC)
+  elseif(ARG_SHARED)
+    set(lib_type SHARED)
+  else()
+    set(lib_type MODULE)
+  endif()
+
+  if("${_Python}" STREQUAL "Python")
+    python_add_library(${target_name} ${lib_type} ${ARG_UNPARSED_ARGUMENTS})
+  elseif("${_Python}" STREQUAL "Python3")
+    python3_add_library(${target_name} ${lib_type} ${ARG_UNPARSED_ARGUMENTS})
+  else()
+    message(FATAL_ERROR "Cannot detect FindPython version: ${_Python}")
+  endif()
+
+  target_link_libraries(${target_name} PRIVATE pybind11::headers)
+
+  if(lib_type STREQUAL "MODULE")
+    target_link_libraries(${target_name} PRIVATE pybind11::module)
+  else()
+    target_link_libraries(${target_name} PRIVATE pybind11::embed)
+  endif()
+
+  if(MSVC)
+    target_link_libraries(${target_name} PRIVATE pybind11::windows_extras)
+  endif()
+
+  # -fvisibility=hidden is required to allow multiple modules compiled against
+  # different pybind versions to work properly, and for some features (e.g.
+  # py::module_local).  We force it on everything inside the `pybind11`
+  # namespace; also turning it on for a pybind module compilation here avoids
+  # potential warnings or issues from having mixed hidden/non-hidden types.
+  if(NOT DEFINED CMAKE_CXX_VISIBILITY_PRESET)
+    set_target_properties(${target_name} PROPERTIES CXX_VISIBILITY_PRESET "hidden")
+  endif()
+
+  if(NOT DEFINED CMAKE_CUDA_VISIBILITY_PRESET)
+    set_target_properties(${target_name} PROPERTIES CUDA_VISIBILITY_PRESET "hidden")
+  endif()
+
+  # If we don't pass a WITH_SOABI or WITHOUT_SOABI, use our own default handling of extensions
+  if(NOT ARG_WITHOUT_SOABI AND NOT "WITH_SOABI" IN_LIST ARG_UNPARSED_ARGUMENTS)
+    pybind11_extension(${target_name})
+  endif()
+
+  if(ARG_NO_EXTRAS)
+    return()
+  endif()
+
+  if(NOT DEFINED CMAKE_INTERPROCEDURAL_OPTIMIZATION)
+    if(ARG_THIN_LTO)
+      target_link_libraries(${target_name} PRIVATE pybind11::thin_lto)
+    else()
+      target_link_libraries(${target_name} PRIVATE pybind11::lto)
+    endif()
+  endif()
+
+  if(NOT MSVC AND NOT ${CMAKE_BUILD_TYPE} MATCHES Debug|RelWithDebInfo)
+    # Strip unnecessary sections of the binary on Linux/macOS
+    pybind11_strip(${target_name})
+  endif()
+
+  if(MSVC)
+    target_link_libraries(${target_name} PRIVATE pybind11::windows_extras)
+  endif()
+
+  if(ARG_OPT_SIZE)
+    target_link_libraries(${target_name} PRIVATE pybind11::opt_size)
+  endif()
+endfunction()
+
+function(pybind11_extension name)
+  # The extension is precomputed
+  set_target_properties(${name} PROPERTIES PREFIX "" SUFFIX "${PYTHON_MODULE_EXTENSION}")
+
+endfunction()

third-party/DPVO/DPViewer/pybind11/tools/pybind11Tools.cmake

@@ -0,0 +1,227 @@
+# tools/pybind11Tools.cmake -- Build system for the pybind11 modules
+#
+# Copyright (c) 2020 Wenzel Jakob <[email protected]>
+#
+# All rights reserved. Use of this source code is governed by a
+# BSD-style license that can be found in the LICENSE file.
+
+# include_guard(global) (pre-CMake 3.10)
+if(TARGET pybind11::python_headers)
+  return()
+endif()
+
+# Built-in in CMake 3.5+
+include(CMakeParseArguments)
+
+if(pybind11_FIND_QUIETLY)
+  set(_pybind11_quiet QUIET)
+else()
+  set(_pybind11_quiet "")
+endif()
+
+# If this is the first run, PYTHON_VERSION can stand in for PYBIND11_PYTHON_VERSION
+if(NOT DEFINED PYBIND11_PYTHON_VERSION AND DEFINED PYTHON_VERSION)
+  message(WARNING "Set PYBIND11_PYTHON_VERSION to search for a specific version, not "
+                  "PYTHON_VERSION (which is an output). Assuming that is what you "
+                  "meant to do and continuing anyway.")
+  set(PYBIND11_PYTHON_VERSION
+      "${PYTHON_VERSION}"
+      CACHE STRING "Python version to use for compiling modules")
+  unset(PYTHON_VERSION)
+  unset(PYTHON_VERSION CACHE)
+elseif(DEFINED PYBIND11_PYTHON_VERSION)
+  # If this is set as a normal variable, promote it
+  set(PYBIND11_PYTHON_VERSION
+      "${PYBIND11_PYTHON_VERSION}"
+      CACHE STRING "Python version to use for compiling modules")
+else()
+  # Make an empty cache variable.
+  set(PYBIND11_PYTHON_VERSION
+      ""
+      CACHE STRING "Python version to use for compiling modules")
+endif()
+
+# A user can set versions manually too
+set(Python_ADDITIONAL_VERSIONS
+    "3.11;3.10;3.9;3.8;3.7;3.6"
+    CACHE INTERNAL "")
+
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}")
+find_package(PythonLibsNew ${PYBIND11_PYTHON_VERSION} MODULE REQUIRED ${_pybind11_quiet})
+list(REMOVE_AT CMAKE_MODULE_PATH -1)
+
+# Makes a normal variable a cached variable
+macro(_PYBIND11_PROMOTE_TO_CACHE NAME)
+  set(_tmp_ptc "${${NAME}}")
+  # CMake 3.21 complains if a cached variable is shadowed by a normal one
+  unset(${NAME})
+  set(${NAME}
+      "${_tmp_ptc}"
+      CACHE INTERNAL "")
+endmacro()
+
+# Cache variables so pybind11_add_module can be used in parent projects
+_pybind11_promote_to_cache(PYTHON_INCLUDE_DIRS)
+_pybind11_promote_to_cache(PYTHON_LIBRARIES)
+_pybind11_promote_to_cache(PYTHON_MODULE_PREFIX)
+_pybind11_promote_to_cache(PYTHON_MODULE_EXTENSION)
+_pybind11_promote_to_cache(PYTHON_VERSION_MAJOR)
+_pybind11_promote_to_cache(PYTHON_VERSION_MINOR)
+_pybind11_promote_to_cache(PYTHON_VERSION)
+_pybind11_promote_to_cache(PYTHON_IS_DEBUG)
+
+if(PYBIND11_MASTER_PROJECT)
+  if(PYTHON_MODULE_EXTENSION MATCHES "pypy")
+    if(NOT DEFINED PYPY_VERSION)
+      execute_process(
+        COMMAND ${PYTHON_EXECUTABLE} -c
+                [=[import sys; sys.stdout.write(".".join(map(str, sys.pypy_version_info[:3])))]=]
+        OUTPUT_VARIABLE pypy_version)
+      set(PYPY_VERSION
+          ${pypy_version}
+          CACHE INTERNAL "")
+    endif()
+    message(STATUS "PYPY ${PYPY_VERSION} (Py ${PYTHON_VERSION})")
+  else()
+    message(STATUS "PYTHON ${PYTHON_VERSION}")
+  endif()
+endif()
+
+# Only add Python for build - must be added during the import for config since
+# it has to be re-discovered.
+#
+# This needs to be an target to it is included after the local pybind11
+# directory, just in case there are multiple versions of pybind11, we want the
+# one we expect.
+add_library(pybind11::python_headers INTERFACE IMPORTED)
+set_property(TARGET pybind11::python_headers PROPERTY INTERFACE_INCLUDE_DIRECTORIES
+                                                      "$<BUILD_INTERFACE:${PYTHON_INCLUDE_DIRS}>")
+set_property(
+  TARGET pybind11::pybind11
+  APPEND
+  PROPERTY INTERFACE_LINK_LIBRARIES pybind11::python_headers)
+
+set(pybind11_INCLUDE_DIRS
+    "${pybind11_INCLUDE_DIR}" "${PYTHON_INCLUDE_DIRS}"
+    CACHE INTERNAL "Directories where pybind11 and possibly Python headers are located")
+
+# Python debug libraries expose slightly different objects before 3.8
+# https://docs.python.org/3.6/c-api/intro.html#debugging-builds
+# https://stackoverflow.com/questions/39161202/how-to-work-around-missing-pymodule-create2-in-amd64-win-python35-d-lib
+if(PYTHON_IS_DEBUG)
+  set_property(
+    TARGET pybind11::pybind11
+    APPEND
+    PROPERTY INTERFACE_COMPILE_DEFINITIONS Py_DEBUG)
+endif()
+
+if(CMAKE_VERSION VERSION_LESS 3.11)
+  set_property(
+    TARGET pybind11::module
+    APPEND
+    PROPERTY
+      INTERFACE_LINK_LIBRARIES
+      pybind11::python_link_helper
+      "$<$<OR:$<PLATFORM_ID:Windows>,$<PLATFORM_ID:Cygwin>>:$<BUILD_INTERFACE:${PYTHON_LIBRARIES}>>"
+  )
+
+  set_property(
+    TARGET pybind11::embed
+    APPEND
+    PROPERTY INTERFACE_LINK_LIBRARIES pybind11::pybind11 $<BUILD_INTERFACE:${PYTHON_LIBRARIES}>)
+else()
+  target_link_libraries(
+    pybind11::module
+    INTERFACE
+      pybind11::python_link_helper
+      "$<$<OR:$<PLATFORM_ID:Windows>,$<PLATFORM_ID:Cygwin>>:$<BUILD_INTERFACE:${PYTHON_LIBRARIES}>>"
+  )
+
+  target_link_libraries(pybind11::embed INTERFACE pybind11::pybind11
+                                                  $<BUILD_INTERFACE:${PYTHON_LIBRARIES}>)
+
+endif()
+
+function(pybind11_extension name)
+  # The prefix and extension are provided by FindPythonLibsNew.cmake
+  set_target_properties(${name} PROPERTIES PREFIX "${PYTHON_MODULE_PREFIX}"
+                                           SUFFIX "${PYTHON_MODULE_EXTENSION}")
+endfunction()
+
+# Build a Python extension module:
+# pybind11_add_module(<name> [MODULE | SHARED] [EXCLUDE_FROM_ALL]
+#                     [NO_EXTRAS] [THIN_LTO] [OPT_SIZE] source1 [source2 ...])
+#
+function(pybind11_add_module target_name)
+  set(options "MODULE;SHARED;EXCLUDE_FROM_ALL;NO_EXTRAS;SYSTEM;THIN_LTO;OPT_SIZE")
+  cmake_parse_arguments(ARG "${options}" "" "" ${ARGN})
+
+  if(ARG_MODULE AND ARG_SHARED)
+    message(FATAL_ERROR "Can't be both MODULE and SHARED")
+  elseif(ARG_SHARED)
+    set(lib_type SHARED)
+  else()
+    set(lib_type MODULE)
+  endif()
+
+  if(ARG_EXCLUDE_FROM_ALL)
+    set(exclude_from_all EXCLUDE_FROM_ALL)
+  else()
+    set(exclude_from_all "")
+  endif()
+
+  add_library(${target_name} ${lib_type} ${exclude_from_all} ${ARG_UNPARSED_ARGUMENTS})
+
+  target_link_libraries(${target_name} PRIVATE pybind11::module)
+
+  if(ARG_SYSTEM)
+    message(
+      STATUS
+        "Warning: this does not have an effect - use NO_SYSTEM_FROM_IMPORTED if using imported targets"
+    )
+  endif()
+
+  pybind11_extension(${target_name})
+
+  # -fvisibility=hidden is required to allow multiple modules compiled against
+  # different pybind versions to work properly, and for some features (e.g.
+  # py::module_local).  We force it on everything inside the `pybind11`
+  # namespace; also turning it on for a pybind module compilation here avoids
+  # potential warnings or issues from having mixed hidden/non-hidden types.
+  if(NOT DEFINED CMAKE_CXX_VISIBILITY_PRESET)
+    set_target_properties(${target_name} PROPERTIES CXX_VISIBILITY_PRESET "hidden")
+  endif()
+
+  if(NOT DEFINED CMAKE_CUDA_VISIBILITY_PRESET)
+    set_target_properties(${target_name} PROPERTIES CUDA_VISIBILITY_PRESET "hidden")
+  endif()
+
+  if(ARG_NO_EXTRAS)
+    return()
+  endif()
+
+  if(NOT DEFINED CMAKE_INTERPROCEDURAL_OPTIMIZATION)
+    if(ARG_THIN_LTO)
+      target_link_libraries(${target_name} PRIVATE pybind11::thin_lto)
+    else()
+      target_link_libraries(${target_name} PRIVATE pybind11::lto)
+    endif()
+  endif()
+
+  if(NOT MSVC AND NOT ${CMAKE_BUILD_TYPE} MATCHES Debug|RelWithDebInfo)
+    pybind11_strip(${target_name})
+  endif()
+
+  if(MSVC)
+    target_link_libraries(${target_name} PRIVATE pybind11::windows_extras)
+  endif()
+
+  if(ARG_OPT_SIZE)
+    target_link_libraries(${target_name} PRIVATE pybind11::opt_size)
+  endif()
+endfunction()
+
+# Provide general way to call common Python commands in "common" file.
+set(_Python
+    PYTHON
+    CACHE INTERNAL "" FORCE)

third-party/DPVO/DPViewer/pybind11/tools/pyproject.toml

@@ -0,0 +1,3 @@
+[build-system]
+requires = ["setuptools>=42", "wheel"]
+build-backend = "setuptools.build_meta"

third-party/DPVO/DPViewer/pybind11/tools/setup_global.py.in

@@ -0,0 +1,59 @@
+#!/usr/bin/env python3
+
+# Setup script for pybind11-global (in the sdist or in tools/setup_global.py in the repository)
+# This package is targeted for easy use from CMake.
+
+import glob
+import os
+import re
+
+# Setuptools has to be before distutils
+from setuptools import setup
+
+from distutils.command.install_headers import install_headers
+
+class InstallHeadersNested(install_headers):
+    def run(self):
+        headers = self.distribution.headers or []
+        for header in headers:
+            # Remove pybind11/include/
+            short_header = header.split("/", 2)[-1]
+
+            dst = os.path.join(self.install_dir, os.path.dirname(short_header))
+            self.mkpath(dst)
+            (out, _) = self.copy_file(header, dst)
+            self.outfiles.append(out)
+
+
+main_headers = glob.glob("pybind11/include/pybind11/*.h")
+detail_headers = glob.glob("pybind11/include/pybind11/detail/*.h")
+stl_headers = glob.glob("pybind11/include/pybind11/stl/*.h")
+cmake_files = glob.glob("pybind11/share/cmake/pybind11/*.cmake")
+headers = main_headers + detail_headers + stl_headers
+
+cmdclass = {"install_headers": InstallHeadersNested}
+$extra_cmd
+
+# This will _not_ affect installing from wheels,
+# only building wheels or installing from SDist.
+# Primarily intended on Windows, where this is sometimes
+# customized (for example, conda-forge uses Library/)
+base = os.environ.get("PYBIND11_GLOBAL_PREFIX", "")
+
+# Must have a separator
+if base and not base.endswith("/"):
+    base += "/"
+
+setup(
+    name="pybind11_global",
+    version="$version",
+    packages=[],
+    headers=headers,
+    data_files=[
+        (base + "share/cmake/pybind11", cmake_files),
+        (base + "include/pybind11", main_headers),
+        (base + "include/pybind11/detail", detail_headers),
+        (base + "include/pybind11/stl", stl_headers),
+    ],
+    cmdclass=cmdclass,
+)

third-party/DPVO/DPViewer/pybind11/tools/setup_main.py.in

@@ -0,0 +1,40 @@
+#!/usr/bin/env python3
+
+# Setup script (in the sdist or in tools/setup_main.py in the repository)
+
+from setuptools import setup
+
+cmdclass = {}
+$extra_cmd
+
+setup(
+    name="pybind11",
+    version="$version",
+    download_url='https://github.com/pybind/pybind11/tarball/v$version',
+    packages=[
+        "pybind11",
+        "pybind11.include.pybind11",
+        "pybind11.include.pybind11.detail",
+        "pybind11.include.pybind11.stl",
+        "pybind11.share.cmake.pybind11",
+    ],
+    package_data={
+        "pybind11": ["py.typed"],
+        "pybind11.include.pybind11": ["*.h"],
+        "pybind11.include.pybind11.detail": ["*.h"],
+        "pybind11.include.pybind11.stl": ["*.h"],
+        "pybind11.share.cmake.pybind11": ["*.cmake"],
+    },
+    extras_require={
+        "global": ["pybind11_global==$version"]
+        },
+    entry_points={
+        "console_scripts": [
+             "pybind11-config = pybind11.__main__:main",
+        ],
+        "pipx.run": [
+             "pybind11 = pybind11.__main__:main",
+        ]
+    },
+    cmdclass=cmdclass
+)

third-party/DPVO/DPViewer/setup.py

@@ -0,0 +1,132 @@
+# -*- coding: utf-8 -*-
+import os
+import re
+import subprocess
+import sys
+import torch
+
+
+from setuptools import setup, Extension
+from setuptools.command.build_ext import build_ext
+
+# Convert distutils Windows platform specifiers to CMake -A arguments
+PLAT_TO_CMAKE = {
+    "win32": "Win32",
+    "win-amd64": "x64",
+    "win-arm32": "ARM",
+    "win-arm64": "ARM64",
+}
+
+
+# A CMakeExtension needs a sourcedir instead of a file list.
+# The name must be the _single_ output extension from the CMake build.
+# If you need multiple extensions, see scikit-build.
+class CMakeExtension(Extension):
+    def __init__(self, name, sourcedir=""):
+        Extension.__init__(self, name, sources=[])
+        self.sourcedir = os.path.abspath(sourcedir)
+
+
+class CMakeBuild(build_ext):
+    def build_extension(self, ext):
+        extdir = os.path.abspath(os.path.dirname(self.get_ext_fullpath(ext.name)))
+
+        # required for auto-detection & inclusion of auxiliary "native" libs
+        if not extdir.endswith(os.path.sep):
+            extdir += os.path.sep
+
+        debug = int(os.environ.get("DEBUG", 0)) if self.debug is None else self.debug
+        cfg = "Debug" if debug else "Release"
+
+        # CMake lets you override the generator - we need to check this.
+        # Can be set with Conda-Build, for example.
+        cmake_generator = os.environ.get("CMAKE_GENERATOR", "")
+
+        # Set Python_EXECUTABLE instead if you use PYBIND11_FINDPYTHON
+        # EXAMPLE_VERSION_INFO shows you how to pass a value into the C++ code
+        # from Python.
+
+        cmake_args = [
+            "-DCMAKE_LIBRARY_OUTPUT_DIRECTORY={}".format(extdir),
+            "-DPYTHON_EXECUTABLE={}".format(sys.executable),
+            "-DCMAKE_BUILD_TYPE={}".format(cfg),  # not used on MSVC, but no harm
+            "-DTORCH_PATH={}".format(torch.__path__[0])
+        ]
+        build_args = ["--verbose"]
+        # Adding CMake arguments set as environment variable
+        # (needed e.g. to build for ARM OSx on conda-forge)
+        if "CMAKE_ARGS" in os.environ:
+            cmake_args += [item for item in os.environ["CMAKE_ARGS"].split(" ") if item]
+
+        # In this example, we pass in the version to C++. You might not need to.
+        cmake_args += [
+            "-DEXAMPLE_VERSION_INFO={}".format(self.distribution.get_version())
+        ]
+
+        if self.compiler.compiler_type != "msvc":
+            # Using Ninja-build since it a) is available as a wheel and b)
+            # multithreads automatically. MSVC would require all variables be
+            # exported for Ninja to pick it up, which is a little tricky to do.
+            # Users can override the generator with CMAKE_GENERATOR in CMake
+            # 3.15+.
+            if not cmake_generator:
+                try:
+                    import ninja  # noqa: F401
+
+                    cmake_args += ["-GNinja"]
+                except ImportError:
+                    pass
+
+        else:
+
+            # Single config generators are handled "normally"
+            single_config = any(x in cmake_generator for x in {"NMake", "Ninja"})
+
+            # CMake allows an arch-in-generator style for backward compatibility
+            contains_arch = any(x in cmake_generator for x in {"ARM", "Win64"})
+
+            # Specify the arch if using MSVC generator, but only if it doesn't
+            # contain a backward-compatibility arch spec already in the
+            # generator name.
+            if not single_config and not contains_arch:
+                cmake_args += ["-A", PLAT_TO_CMAKE[self.plat_name]]
+
+            # Multi-config generators have a different way to specify configs
+            if not single_config:
+                cmake_args += [
+                    "-DCMAKE_LIBRARY_OUTPUT_DIRECTORY_{}={}".format(cfg.upper(), extdir)
+                ]
+                build_args += ["--config", cfg]
+
+        if sys.platform.startswith("darwin"):
+            # Cross-compile support for macOS - respect ARCHFLAGS if set
+            archs = re.findall(r"-arch (\S+)", os.environ.get("ARCHFLAGS", ""))
+            if archs:
+                cmake_args += ["-DCMAKE_OSX_ARCHITECTURES={}".format(";".join(archs))]
+
+        build_args += ["-j"]
+
+        if not os.path.exists(self.build_temp):
+            os.makedirs(self.build_temp)
+
+        subprocess.check_call(
+            ["cmake", ext.sourcedir] + cmake_args, cwd=self.build_temp,
+        )
+
+        subprocess.check_call(
+            ["cmake", "--build", "."] + build_args, cwd=self.build_temp
+        )
+
+
+# The information here can also be placed in setup.cfg - better separation of
+# logic and declaration, and simpler if you include description/version in a file.
+setup(
+    name="dpviewer",
+    version="0.0.1",
+    author="Zachary Teed",
+    packages=['dpviewer'],
+    ext_modules=[CMakeExtension("dpviewer")],
+    cmdclass={"build_ext": CMakeBuild},
+    zip_safe=False,
+    extras_require={"test": ["pytest"]},
+)

third-party/DPVO/dpvo/altcorr/__init__.py

@@ -0,0 +1 @@
+from .correlation import corr, patchify

third-party/DPVO/dpvo/altcorr/correlation.cpp

@@ -0,0 +1,63 @@
+#include <torch/extension.h>
+#include <vector>
+
+// CUDA forward declarations
+std::vector<torch::Tensor> corr_cuda_forward(
+    torch::Tensor fmap1,
+    torch::Tensor fmap2,
+    torch::Tensor coords,
+    torch::Tensor ii,
+    torch::Tensor jj,
+    int radius);
+
+std::vector<torch::Tensor> corr_cuda_backward(
+  torch::Tensor fmap1,
+  torch::Tensor fmap2,
+  torch::Tensor coords,
+  torch::Tensor ii,
+  torch::Tensor jj,
+  torch::Tensor corr_grad,
+  int radius);
+
+std::vector<torch::Tensor> patchify_cuda_forward(
+    torch::Tensor net, torch::Tensor coords, int radius);
+
+std::vector<torch::Tensor> patchify_cuda_backward(
+    torch::Tensor net, torch::Tensor coords, torch::Tensor gradient, int radius);
+
+std::vector<torch::Tensor> corr_forward(
+    torch::Tensor fmap1,
+    torch::Tensor fmap2,
+    torch::Tensor coords,
+    torch::Tensor ii,
+    torch::Tensor jj, int radius) {
+  return corr_cuda_forward(fmap1, fmap2, coords, ii, jj, radius);
+}
+
+std::vector<torch::Tensor> corr_backward(
+    torch::Tensor fmap1,
+    torch::Tensor fmap2,
+    torch::Tensor coords,
+    torch::Tensor ii,
+    torch::Tensor jj,
+    torch::Tensor corr_grad, int radius) {
+  return corr_cuda_backward(fmap1, fmap2, coords, ii, jj, corr_grad, radius);
+}
+
+std::vector<torch::Tensor> patchify_forward(
+    torch::Tensor net, torch::Tensor coords, int radius) {
+  return patchify_cuda_forward(net, coords, radius);
+}
+
+std::vector<torch::Tensor> patchify_backward(
+    torch::Tensor net, torch::Tensor coords, torch::Tensor gradient, int radius) {
+  return patchify_cuda_backward(net, coords, gradient, radius);
+}
+
+PYBIND11_MODULE(TORCH_EXTENSION_NAME, m) {
+  m.def("forward", &corr_forward, "CORR forward");
+  m.def("backward", &corr_backward, "CORR backward");
+
+  m.def("patchify_forward", &patchify_forward, "PATCHIFY forward");
+  m.def("patchify_backward", &patchify_backward, "PATCHIFY backward");
+}

third-party/DPVO/dpvo/altcorr/correlation.py

@@ -0,0 +1,74 @@
+import torch
+import cuda_corr
+
+class CorrLayer(torch.autograd.Function):
+    @staticmethod
+    def forward(ctx, fmap1, fmap2, coords, ii, jj, radius, dropout):
+        """ forward correlation """
+        ctx.save_for_backward(fmap1, fmap2, coords, ii, jj)
+        ctx.radius = radius
+        ctx.dropout = dropout
+        corr, = cuda_corr.forward(fmap1, fmap2, coords, ii, jj, radius)
+
+        return corr
+
+    @staticmethod
+    def backward(ctx, grad):
+        """ backward correlation """
+        fmap1, fmap2, coords, ii, jj = ctx.saved_tensors
+
+        if ctx.dropout < 1:
+            perm = torch.rand(len(ii), device="cuda") < ctx.dropout
+            coords = coords[:,perm]
+            grad = grad[:,perm]
+            ii = ii[perm]
+            jj = jj[perm]
+
+        fmap1_grad, fmap2_grad = \
+            cuda_corr.backward(fmap1, fmap2, coords, ii, jj, grad, ctx.radius)
+
+        return fmap1_grad, fmap2_grad, None, None, None, None, None
+
+
+class PatchLayer(torch.autograd.Function):
+    @staticmethod
+    def forward(ctx, net, coords, radius):
+        """ forward patchify """
+        ctx.radius = radius
+        ctx.save_for_backward(net, coords)
+        
+        patches, = cuda_corr.patchify_forward(net, coords, radius)
+        return patches
+
+    @staticmethod
+    def backward(ctx, grad):
+        """ backward patchify """
+        net, coords = ctx.saved_tensors
+        grad, = cuda_corr.patchify_backward(net, coords, grad, ctx.radius)
+
+        return grad, None, None
+
+def patchify(net, coords, radius, mode='bilinear'):
+    """ extract patches """
+
+    patches = PatchLayer.apply(net, coords, radius)
+
+    if mode == 'bilinear':
+        offset = (coords - coords.floor()).to(net.device)
+        dx, dy = offset[:,:,None,None,None].unbind(dim=-1)
+
+        d = 2 * radius + 1
+        x00 = (1-dy) * (1-dx) * patches[...,:d,:d]
+        x01 = (1-dy) * (  dx) * patches[...,:d,1:]
+        x10 = (  dy) * (1-dx) * patches[...,1:,:d]
+        x11 = (  dy) * (  dx) * patches[...,1:,1:]
+
+        return x00 + x01 + x10 + x11
+
+    return patches
+    
+
+def corr(fmap1, fmap2, coords, ii, jj, radius=1, dropout=1):
+    return CorrLayer.apply(fmap1, fmap2, coords, ii, jj, radius, dropout)
+
+

third-party/DPVO/dpvo/altcorr/correlation_kernel.cu

@@ -0,0 +1,333 @@
+#include <torch/extension.h>
+#include <THC/THCAtomics.cuh>
+#include <vector>
+#include <iostream>
+
+using namespace torch::indexing;
+
+#define THREADS 256
+#define BLOCKS(n) (n + THREADS - 1) / THREADS
+
+__forceinline__ __device__
+bool within_bounds(int h, int w, int H, int W) {
+  return h >= 0 && h < H && w >= 0 && w < W;
+}
+
+template <typename scalar_t>
+__global__ void patchify_forward_kernel(int R,
+    const torch::PackedTensorAccessor32<scalar_t,4,torch::RestrictPtrTraits> net,
+    const torch::PackedTensorAccessor32<float,3,torch::RestrictPtrTraits> coords,
+    torch::PackedTensorAccessor32<scalar_t,5,torch::RestrictPtrTraits> patches)
+{
+  // diameter
+  const int D = 2*R + 2;
+
+  const int B = coords.size(0);
+  const int M = coords.size(1);
+  const int C = net.size(1);
+  const int H = net.size(2);
+  const int W = net.size(3);
+
+  int n = blockIdx.x * blockDim.x + threadIdx.x;
+  if (n < B * M * D * D) {
+    const int ii = n % D; n /= D;
+    const int jj = n % D; n /= D;
+    const int  m = n % M; n /= M;
+
+    const float x = coords[n][m][0];
+    const float y = coords[n][m][1];
+    const int i = static_cast<int>(floor(y)) + (ii - R);
+    const int j = static_cast<int>(floor(x)) + (jj - R);
+
+    if (within_bounds(i, j, H, W)) {
+      for (int k=0; k<C; k++)
+        patches[n][m][k][ii][jj] = net[n][k][i][j];
+    }
+  }
+}
+
+template <typename scalar_t>
+__global__ void patchify_backward_kernel(int R,
+    const torch::PackedTensorAccessor32<scalar_t,5,torch::RestrictPtrTraits> patch_gradient,
+    const torch::PackedTensorAccessor32<float,3,torch::RestrictPtrTraits> coords,
+    torch::PackedTensorAccessor32<scalar_t,4,torch::RestrictPtrTraits> gradient)
+{
+  // diameter
+  const int D = 2*R + 2;
+
+  const int B = coords.size(0);
+  const int M = coords.size(1);
+  const int C = gradient.size(1);
+  const int H = gradient.size(2);
+  const int W = gradient.size(3);
+
+  int n = blockIdx.x * blockDim.x + threadIdx.x;
+  if (n < B * M * D * D) {
+    const int ii = n % D; n /= D;
+    const int jj = n % D; n /= D;
+    const int  m = n % M; n /= M;
+
+    const float x = coords[n][m][0];
+    const float y = coords[n][m][1];
+    const int i = static_cast<int>(floor(y)) + (ii - R);
+    const int j = static_cast<int>(floor(x)) + (jj - R);
+
+    if (within_bounds(i, j, H, W)) {
+      for (int k=0; k<C; k++)
+        atomicAdd(&gradient[n][k][i][j], patch_gradient[n][m][k][ii][jj]);
+    }
+  }
+}
+
+template <typename scalar_t>
+__global__ void corr_forward_kernel(int R,
+    const torch::PackedTensorAccessor32<scalar_t,5,torch::RestrictPtrTraits> fmap1,
+    const torch::PackedTensorAccessor32<scalar_t,5,torch::RestrictPtrTraits> fmap2,
+    const torch::PackedTensorAccessor32<float,5,torch::RestrictPtrTraits> coords,
+    const torch::PackedTensorAccessor32<long,1,torch::RestrictPtrTraits> us,
+    const torch::PackedTensorAccessor32<long,1,torch::RestrictPtrTraits> vs,
+    torch::PackedTensorAccessor32<scalar_t,6,torch::RestrictPtrTraits> corr)
+{
+  // diameter
+  const int D = 2*R + 2;
+
+  const int B = coords.size(0);
+  const int M = coords.size(1);
+  const int H = coords.size(3);
+  const int W = coords.size(4);
+
+  const int C = fmap1.size(2);
+  const int H2 = fmap2.size(3);
+  const int W2 = fmap2.size(4);
+
+  int n = blockIdx.x * blockDim.x + threadIdx.x;
+
+  if (n < B * M * H * W * D * D) {
+    const int jj = n % D; n /= D;
+    const int ii = n % D; n /= D;
+    const int j0 = n % W; n /= W;
+    const int i0 = n % H; n /= H;
+    const int  m = n % M; n /= M;
+
+    const int ix = us[m];
+    const int jx = vs[m];
+
+    const float x = coords[n][m][0][i0][j0];
+    const float y = coords[n][m][1][i0][j0];
+
+    const int i1 = static_cast<int>(floor(y)) + (ii - R);
+    const int j1 = static_cast<int>(floor(x)) + (jj - R);
+
+    scalar_t s = 0;
+    if (within_bounds(i1, j1, H2, W2)) {
+
+      #pragma unroll 8
+      for (int i=0; i<C; i+=8) {
+        scalar_t f1[8]; for (int j=0; j<8; j++) f1[j] = fmap1[n][ix][i+j][i0][j0];
+        scalar_t f2[8]; for (int j=0; j<8; j++) f2[j] = fmap2[n][jx][i+j][i1][j1];
+
+        #pragma unroll
+        for (int j=0; j<8; j++) s += f1[j] * f2[j];
+      }
+    }
+
+    corr[n][m][ii][jj][i0][j0] = s;
+  }
+}
+
+
+template <typename scalar_t>
+__global__ void corr_backward_kernel(int R,
+    const torch::PackedTensorAccessor32<scalar_t,5,torch::RestrictPtrTraits> fmap1,
+    const torch::PackedTensorAccessor32<scalar_t,5,torch::RestrictPtrTraits> fmap2,
+    const torch::PackedTensorAccessor32<float,5,torch::RestrictPtrTraits> coords,
+    const torch::PackedTensorAccessor32<long,1,torch::RestrictPtrTraits> us,
+    const torch::PackedTensorAccessor32<long,1,torch::RestrictPtrTraits> vs,
+    const torch::PackedTensorAccessor32<float,6,torch::RestrictPtrTraits> corr_grad,
+    torch::PackedTensorAccessor32<scalar_t,5,torch::RestrictPtrTraits> fmap1_grad,
+    torch::PackedTensorAccessor32<scalar_t,5,torch::RestrictPtrTraits> fmap2_grad)
+{
+  // diameter
+  const int D = 2*R + 2;
+
+  const int B = coords.size(0);
+  const int M = coords.size(1);
+  const int H = coords.size(3);
+  const int W = coords.size(4);
+
+  const int C = fmap1.size(2);
+  const int H2 = fmap2.size(3);
+  const int W2 = fmap2.size(4);
+
+  int n = blockIdx.x * blockDim.x + threadIdx.x;
+
+  if (n < B * M * H * W * D * D) {
+    const int jj = n % D; n /= D;
+    const int ii = n % D; n /= D;
+    const int j0 = n % W; n /= W;
+    const int i0 = n % H; n /= H;
+    const int  m = n % M; n /= M;
+
+    const int ix = us[m];
+    const int jx = vs[m];
+
+    const float x = coords[n][m][0][i0][j0];
+    const float y = coords[n][m][1][i0][j0];
+
+    const int i1 = static_cast<int>(floor(y)) + (ii - R);
+    const int j1 = static_cast<int>(floor(x)) + (jj - R);
+
+    const scalar_t g = (scalar_t) corr_grad[n][m][ii][jj][i0][j0];
+
+    if (within_bounds(i1, j1, H2, W2)) {
+      #pragma unroll 32
+      for (int i=0; i<C; i++) {
+        atomicAdd(&fmap1_grad[n][ix][i][i0][j0], g * fmap2[n][jx][i][i1][j1]);
+        atomicAdd(&fmap2_grad[n][jx][i][i1][j1], g * fmap1[n][ix][i][i0][j0]);
+      }
+    }
+  }
+}
+
+
+std::vector<torch::Tensor> corr_cuda_forward(
+  torch::Tensor fmap1,
+  torch::Tensor fmap2,
+  torch::Tensor coords,
+  torch::Tensor ii,
+  torch::Tensor jj,
+  int radius)
+{
+  const int B = coords.size(0);
+  const int M = coords.size(1);
+
+  const int H = coords.size(3);
+  const int W = coords.size(4);
+  const int D = 2 * radius + 2;
+
+  auto opts = fmap1.options();
+  auto corr = torch::empty({B, M, D, D, H, W}, opts);
+
+  AT_DISPATCH_FLOATING_TYPES_AND_HALF(fmap1.type(), "corr_forward_kernel", ([&] {
+      corr_forward_kernel<scalar_t><<<BLOCKS(B * M * H * W * D * D), THREADS>>>(radius,
+        fmap1.packed_accessor32<scalar_t,5,torch::RestrictPtrTraits>(),
+        fmap2.packed_accessor32<scalar_t,5,torch::RestrictPtrTraits>(),
+        coords.packed_accessor32<float,5,torch::RestrictPtrTraits>(),
+        ii.packed_accessor32<long,1,torch::RestrictPtrTraits>(),
+        jj.packed_accessor32<long,1,torch::RestrictPtrTraits>(),
+        corr.packed_accessor32<scalar_t,6,torch::RestrictPtrTraits>());
+  }));
+
+  torch::Tensor x = coords.index({Slice(), Slice(), 0, None, None});
+  torch::Tensor y = coords.index({Slice(), Slice(), 1, None, None});
+  torch::Tensor dx = x - x.floor(); dx = dx.to(fmap1.dtype());
+  torch::Tensor dy = y - y.floor(); dy = dy.to(fmap2.dtype());
+
+  torch::Tensor out;
+  out  = (1 - dx) * (1 - dy) * corr.index({Slice(), Slice(), Slice(0, D-1), Slice(0, D-1)});
+  out +=     (dx) * (1 - dy) * corr.index({Slice(), Slice(), Slice(0, D-1), Slice(1, D-0)});
+  out += (1 - dx) *     (dy) * corr.index({Slice(), Slice(), Slice(1, D-0), Slice(0, D-1)});
+  out +=     (dx) *     (dy) * corr.index({Slice(), Slice(), Slice(1, D-0), Slice(1, D-0)});
+
+  return { out.permute({0,1,3,2,4,5}) };
+}
+
+
+std::vector<torch::Tensor> corr_cuda_backward(
+  torch::Tensor fmap1,
+  torch::Tensor fmap2,
+  torch::Tensor coords,
+  torch::Tensor ii,
+  torch::Tensor jj,
+  torch::Tensor grad,
+  int radius)
+{
+  const int B = coords.size(0);
+  const int M = coords.size(1);
+
+  const int H = coords.size(3);
+  const int W = coords.size(4);
+  const int D = 2 * radius + 2;
+   
+  grad = grad.permute({0,1,3,2,4,5}).contiguous();
+  torch::Tensor x = coords.index({Slice(), Slice(), 0, None, None});
+  torch::Tensor y = coords.index({Slice(), Slice(), 1, None, None});
+  torch::Tensor dx = x - x.floor();
+  torch::Tensor dy = y - y.floor();
+
+  auto opts = torch::TensorOptions().dtype(torch::kFloat).device(torch::kCUDA);
+  torch::Tensor g1 = torch::zeros({B, M, D, D, H, W}, grad.options());
+  torch::Tensor g2 = torch::zeros({B, M, D, D, H, W}, grad.options());
+  torch::Tensor g3 = torch::zeros({B, M, D, D, H, W}, grad.options());
+  torch::Tensor g4 = torch::zeros({B, M, D, D, H, W}, grad.options());
+  
+  g1.index_put_({Slice(), Slice(), Slice(0, D-1), Slice(0, D-1)}, (1 - dx) * (1 - dy) * grad);
+  g2.index_put_({Slice(), Slice(), Slice(0, D-1), Slice(1, D-0)},     (dx) * (1 - dy) * grad); 
+  g3.index_put_({Slice(), Slice(), Slice(1, D-0), Slice(0, D-1)}, (1 - dx) *     (dy) * grad);
+  g4.index_put_({Slice(), Slice(), Slice(1, D-0), Slice(1, D-0)},     (dx) *     (dy) * grad);
+
+  torch::Tensor corr_grad = g1 + g2 + g3 + g4;
+  auto fmap1_grad = torch::zeros_like(fmap1);
+  auto fmap2_grad = torch::zeros_like(fmap2);
+
+  AT_DISPATCH_FLOATING_TYPES_AND_HALF(fmap1.type(), "corr_backward_kernel", ([&] {
+    corr_backward_kernel<scalar_t><<<BLOCKS(B * M * H * W * D * D), THREADS>>>(radius,
+      fmap1.packed_accessor32<scalar_t,5,torch::RestrictPtrTraits>(),
+      fmap2.packed_accessor32<scalar_t,5,torch::RestrictPtrTraits>(),
+      coords.packed_accessor32<float,5,torch::RestrictPtrTraits>(),
+      ii.packed_accessor32<long,1,torch::RestrictPtrTraits>(),
+      jj.packed_accessor32<long,1,torch::RestrictPtrTraits>(),
+      corr_grad.packed_accessor32<float,6,torch::RestrictPtrTraits>(),
+      fmap1_grad.packed_accessor32<scalar_t,5,torch::RestrictPtrTraits>(),
+      fmap2_grad.packed_accessor32<scalar_t,5,torch::RestrictPtrTraits>());
+  }));
+
+  return {fmap1_grad, fmap2_grad};
+}
+
+std::vector<torch::Tensor> patchify_cuda_forward(
+  torch::Tensor net, torch::Tensor coords, int radius)
+{
+  const int B = coords.size(0);
+  const int M = coords.size(1);
+  const int C = net.size(1);
+  const int D = 2 * radius + 2;
+
+  auto opts = net.options();
+  auto patches = torch::zeros({B, M, C, D, D}, opts);
+
+  AT_DISPATCH_FLOATING_TYPES_AND_HALF(net.type(), "patchify_forward_kernel", ([&] {
+      patchify_forward_kernel<scalar_t><<<BLOCKS(B * M * D * D), THREADS>>>(radius,
+        net.packed_accessor32<scalar_t,4,torch::RestrictPtrTraits>(),
+        coords.packed_accessor32<float,3,torch::RestrictPtrTraits>(),
+        patches.packed_accessor32<scalar_t,5,torch::RestrictPtrTraits>());
+  }));
+
+  return { patches };
+}
+
+
+std::vector<torch::Tensor> patchify_cuda_backward(
+  torch::Tensor net,
+  torch::Tensor coords,
+  torch::Tensor gradient,
+  int radius)
+{
+  const int B = coords.size(0);
+  const int M = coords.size(1);
+  const int C = net.size(1);
+  const int H = net.size(2);
+  const int W = net.size(3);
+  const int D = 2 * radius + 2;
+  
+  torch::Tensor net_gradient = torch::zeros_like(net);
+  
+  AT_DISPATCH_FLOATING_TYPES_AND_HALF(net.type(), "patchify_backward_kernel", ([&] {
+    patchify_backward_kernel<scalar_t><<<BLOCKS(B * M * D * D), THREADS>>>(radius,
+      gradient.packed_accessor32<scalar_t,5,torch::RestrictPtrTraits>(),
+      coords.packed_accessor32<float,3,torch::RestrictPtrTraits>(),
+      net_gradient.packed_accessor32<scalar_t,4,torch::RestrictPtrTraits>());
+  }));
+
+  return { net_gradient };
+}

third-party/DPVO/dpvo/ba.py

@@ -0,0 +1,182 @@
+import torch
+from torch_scatter import scatter_sum
+
+from . import fastba
+from . import lietorch
+from .lietorch import SE3
+
+from .utils import Timer
+
+from . import projective_ops as pops
+
+class CholeskySolver(torch.autograd.Function):
+    @staticmethod
+    def forward(ctx, H, b):
+        # don't crash training if cholesky decomp fails
+        U, info = torch.linalg.cholesky_ex(H)
+
+        if torch.any(info):
+            ctx.failed = True
+            return torch.zeros_like(b)
+
+        xs = torch.cholesky_solve(b, U)
+        ctx.save_for_backward(U, xs)
+        ctx.failed = False
+
+        return xs
+
+    @staticmethod
+    def backward(ctx, grad_x):
+        if ctx.failed:
+            return None, None
+
+        U, xs = ctx.saved_tensors
+        dz = torch.cholesky_solve(grad_x, U)
+        dH = -torch.matmul(xs, dz.transpose(-1,-2))
+
+        return dH, dz
+
+# utility functions for scattering ops
+def safe_scatter_add_mat(A, ii, jj, n, m):
+    v = (ii >= 0) & (jj >= 0) & (ii < n) & (jj < m)
+    return scatter_sum(A[:,v], ii[v]*m + jj[v], dim=1, dim_size=n*m)
+
+def safe_scatter_add_vec(b, ii, n):
+    v = (ii >= 0) & (ii < n)
+    return scatter_sum(b[:,v], ii[v], dim=1, dim_size=n)
+
+# apply retraction operator to inv-depth maps
+def disp_retr(disps, dz, ii):
+    ii = ii.to(device=dz.device)
+    return disps + scatter_sum(dz, ii, dim=1, dim_size=disps.shape[1])
+
+# apply retraction operator to poses
+def pose_retr(poses, dx, ii):
+    ii = ii.to(device=dx.device)
+    return poses.retr(scatter_sum(dx, ii, dim=1, dim_size=poses.shape[1]))
+
+def block_matmul(A, B):
+    """ block matrix multiply """
+    b, n1, m1, p1, q1 = A.shape
+    b, n2, m2, p2, q2 = B.shape
+    A = A.permute(0, 1, 3, 2, 4).reshape(b, n1*p1, m1*q1)
+    B = B.permute(0, 1, 3, 2, 4).reshape(b, n2*p2, m2*q2)
+    return torch.matmul(A, B).reshape(b, n1, p1, m2, q2).permute(0, 1, 3, 2, 4)
+
+def block_solve(A, B, ep=1.0, lm=1e-4):
+    """ block matrix solve """
+    b, n1, m1, p1, q1 = A.shape
+    b, n2, m2, p2, q2 = B.shape
+    A = A.permute(0, 1, 3, 2, 4).reshape(b, n1*p1, m1*q1)
+    B = B.permute(0, 1, 3, 2, 4).reshape(b, n2*p2, m2*q2)
+
+    A = A + (ep + lm * A) * torch.eye(n1*p1, device=A.device)
+
+    X = CholeskySolver.apply(A, B)
+    return X.reshape(b, n1, p1, m2, q2).permute(0, 1, 3, 2, 4)
+
+
+def block_show(A):
+    import matplotlib.pyplot as plt
+    b, n1, m1, p1, q1 = A.shape
+    A = A.permute(0, 1, 3, 2, 4).reshape(b, n1*p1, m1*q1)
+    plt.imshow(A[0].detach().cpu().numpy())
+    plt.show()
+
+def BA(poses, patches, intrinsics, targets, weights, lmbda, ii, jj, kk, bounds, ep=100.0, PRINT=False, fixedp=1, structure_only=False):
+    """ bundle adjustment """
+
+    b = 1
+    n = max(ii.max().item(), jj.max().item()) + 1
+
+    coords, v, (Ji, Jj, Jz) = \
+        pops.transform(poses, patches, intrinsics, ii, jj, kk, jacobian=True)
+
+    p = coords.shape[3]
+    r = targets - coords[...,p//2,p//2,:]
+
+    v *= (r.norm(dim=-1) < 250).float()
+
+    in_bounds = \
+        (coords[...,p//2,p//2,0] > bounds[0]) & \
+        (coords[...,p//2,p//2,1] > bounds[1]) & \
+        (coords[...,p//2,p//2,0] < bounds[2]) & \
+        (coords[...,p//2,p//2,1] < bounds[3])
+
+    v *= in_bounds.float()
+
+    if PRINT:
+        print((r * v[...,None]).norm(dim=-1).mean().item())
+
+    r = (v[...,None] * r).unsqueeze(dim=-1)    
+    weights = (v[...,None] * weights).unsqueeze(dim=-1)
+
+    wJiT = (weights * Ji).transpose(2,3)
+    wJjT = (weights * Jj).transpose(2,3)
+    wJzT = (weights * Jz).transpose(2,3)
+
+    Bii = torch.matmul(wJiT, Ji)
+    Bij = torch.matmul(wJiT, Jj)
+    Bji = torch.matmul(wJjT, Ji)
+    Bjj = torch.matmul(wJjT, Jj)
+
+    Eik = torch.matmul(wJiT, Jz)
+    Ejk = torch.matmul(wJjT, Jz)
+
+    vi = torch.matmul(wJiT, r)
+    vj = torch.matmul(wJjT, r)
+
+    # fix first pose
+    ii = ii.clone()
+    jj = jj.clone()
+
+    n = n - fixedp
+    ii = ii - fixedp
+    jj = jj - fixedp
+
+    kx, kk = torch.unique(kk, return_inverse=True, sorted=True)
+    m = len(kx)
+
+    B = safe_scatter_add_mat(Bii, ii, ii, n, n).view(b, n, n, 6, 6) + \
+        safe_scatter_add_mat(Bij, ii, jj, n, n).view(b, n, n, 6, 6) + \
+        safe_scatter_add_mat(Bji, jj, ii, n, n).view(b, n, n, 6, 6) + \
+        safe_scatter_add_mat(Bjj, jj, jj, n, n).view(b, n, n, 6, 6)
+
+    E = safe_scatter_add_mat(Eik, ii, kk, n, m).view(b, n, m, 6, 1) + \
+        safe_scatter_add_mat(Ejk, jj, kk, n, m).view(b, n, m, 6, 1) 
+
+    C = safe_scatter_add_vec(torch.matmul(wJzT, Jz), kk, m)
+
+    v = safe_scatter_add_vec(vi, ii, n).view(b, n, 1, 6, 1) + \
+        safe_scatter_add_vec(vj, jj, n).view(b, n, 1, 6, 1)
+
+    w = safe_scatter_add_vec(torch.matmul(wJzT,  r), kk, m)
+
+    if isinstance(lmbda, torch.Tensor):
+        lmbda = lmbda.reshape(*C.shape)
+        
+    Q = 1.0 / (C + lmbda)
+    
+    ### solve w/ schur complement ###
+    EQ = E * Q[:,None]
+
+    if structure_only or n == 0:
+        dZ = (Q * w).view(b, -1, 1, 1)
+
+    else:
+        S = B - block_matmul(EQ, E.permute(0,2,1,4,3))
+        y = v - block_matmul(EQ, w.unsqueeze(dim=2))
+        dX = block_solve(S, y, ep=ep, lm=1e-4)
+
+        dZ = Q * (w - block_matmul(E.permute(0,2,1,4,3), dX).squeeze(dim=-1))
+        dX = dX.view(b, -1, 6)
+        dZ = dZ.view(b, -1, 1, 1)
+
+    x, y, disps = patches.unbind(dim=2)
+    disps = disp_retr(disps, dZ, kx).clamp(min=1e-3, max=10.0)
+    patches = torch.stack([x, y, disps], dim=2)
+
+    if not structure_only and n > 0:
+        poses = pose_retr(poses, dX, fixedp + torch.arange(n))
+
+    return poses, patches

third-party/DPVO/dpvo/blocks.py

@@ -0,0 +1,118 @@
+import torch
+import torch.nn as nn
+import torch.nn.functional as F
+
+import torch_scatter
+
+class LayerNorm1D(nn.Module):
+    def __init__(self, dim):
+        super(LayerNorm1D, self).__init__()
+        self.norm = nn.LayerNorm(dim, eps=1e-4)
+
+    def forward(self, x):
+        return self.norm(x.transpose(1,2)).transpose(1,2)
+
+class GatedResidual(nn.Module):
+    def __init__(self, dim):
+        super().__init__()
+
+        self.gate = nn.Sequential(
+            nn.Linear(dim, dim),
+            nn.Sigmoid())
+
+        self.res = nn.Sequential(
+            nn.Linear(dim, dim),
+            nn.ReLU(inplace=True),
+            nn.Linear(dim, dim))
+
+    def forward(self, x):
+        return x + self.gate(x) * self.res(x)
+
+class SoftAgg(nn.Module):
+    def __init__(self, dim=512, expand=True):
+        super(SoftAgg, self).__init__()
+        self.dim = dim
+        self.expand = expand
+        self.f = nn.Linear(self.dim, self.dim)
+        self.g = nn.Linear(self.dim, self.dim)
+        self.h = nn.Linear(self.dim, self.dim)
+
+    def forward(self, x, ix):
+        _, jx = torch.unique(ix, return_inverse=True)
+        w = torch_scatter.scatter_softmax(self.g(x), jx, dim=1)
+        y = torch_scatter.scatter_sum(self.f(x) * w, jx, dim=1)
+
+        if self.expand:
+            return self.h(y)[:,jx]
+            
+        return self.h(y)
+
+class SoftAggBasic(nn.Module):
+    def __init__(self, dim=512, expand=True):
+        super(SoftAggBasic, self).__init__()
+        self.dim = dim
+        self.expand = expand
+        self.f = nn.Linear(self.dim, self.dim)
+        self.g = nn.Linear(self.dim,        1)
+        self.h = nn.Linear(self.dim, self.dim)
+
+    def forward(self, x, ix):
+        _, jx = torch.unique(ix, return_inverse=True)
+        w = torch_scatter.scatter_softmax(self.g(x), jx, dim=1)
+        y = torch_scatter.scatter_sum(self.f(x) * w, jx, dim=1)
+
+        if self.expand:
+            return self.h(y)[:,jx]
+            
+        return self.h(y)
+
+
+### Gradient Clipping and Zeroing Operations ###
+
+GRAD_CLIP = 0.1
+
+class GradClip(torch.autograd.Function):
+    @staticmethod
+    def forward(ctx, x):
+        return x
+
+    @staticmethod
+    def backward(ctx, grad_x):
+        grad_x = torch.where(torch.isnan(grad_x), torch.zeros_like(grad_x), grad_x)
+        return grad_x.clamp(min=-0.01, max=0.01)
+
+class GradientClip(nn.Module):
+    def __init__(self):
+        super(GradientClip, self).__init__()
+
+    def forward(self, x):
+        return GradClip.apply(x)
+
+class GradZero(torch.autograd.Function):
+    @staticmethod
+    def forward(ctx, x):
+        return x
+
+    @staticmethod
+    def backward(ctx, grad_x):
+        grad_x = torch.where(torch.isnan(grad_x), torch.zeros_like(grad_x), grad_x)
+        grad_x = torch.where(torch.abs(grad_x) > GRAD_CLIP, torch.zeros_like(grad_x), grad_x)
+        return grad_x
+
+class GradientZero(nn.Module):
+    def __init__(self):
+        super(GradientZero, self).__init__()
+
+    def forward(self, x):
+        return GradZero.apply(x)
+
+
+class GradMag(torch.autograd.Function):
+    @staticmethod
+    def forward(ctx, x):
+        return x
+
+    @staticmethod
+    def backward(ctx, grad_x):
+        print(grad_x.abs().mean())
+        return grad_x

third-party/DPVO/dpvo/config.py

@@ -0,0 +1,38 @@
+from yacs.config import CfgNode as CN
+
+_C = CN()
+
+# max number of keyframes
+_C.BUFFER_SIZE = 4096
+
+# bias patch selection towards high gradient regions?
+_C.CENTROID_SEL_STRAT = 'RANDOM'
+
+# VO config (increase for better accuracy)
+_C.PATCHES_PER_FRAME = 80
+_C.REMOVAL_WINDOW = 20
+_C.OPTIMIZATION_WINDOW = 12
+_C.PATCH_LIFETIME = 12
+
+# threshold for keyframe removal
+_C.KEYFRAME_INDEX = 4
+_C.KEYFRAME_THRESH = 12.5
+
+# camera motion model
+_C.MOTION_MODEL = 'DAMPED_LINEAR'
+_C.MOTION_DAMPING = 0.5
+
+_C.MIXED_PRECISION = True
+
+# Loop closure
+_C.LOOP_CLOSURE = False
+_C.BACKEND_THRESH = 64.0
+_C.MAX_EDGE_AGE = 1000
+_C.GLOBAL_OPT_FREQ = 15
+
+# Classic loop closure
+_C.CLASSIC_LOOP_CLOSURE = False
+_C.LOOP_CLOSE_WINDOW_SIZE = 3
+_C.LOOP_RETR_THRESH = 0.04
+
+cfg = _C

third-party/DPVO/dpvo/data_readers/__init__.py

@@ -0,0 +1 @@
+