text: #pragma once
  #include <ATen/core/ivalue.h>
  #include <ATen/core/jit_type.h>
  #include <torch/csrc/WindowsTorchApiMacro.h>
  #include <torch/csrc/jit/frontend/source_range.h>
  #include <torch/csrc/jit/ir/scope.h>
  
  // helpers for handling constants in the IR
  // - create constant nodes from ints, floats, complex, intlist, Tensors, and
  // other types
  // - implement primitive constant ops.
  namespace torch {
  namespace jit {
  
  using ::c10::IValue;
  
  struct Graph;
  struct Value;
  
  // thrown when insertConstant cannot encode the IValue into a graph
  struct TORCH_API constant_not_supported_error : public std::runtime_error {
    using runtime_error::runtime_error;
  };
  
  TORCH_API Value* insertConstant(
      Graph& g,
      const IValue& val,
      c10::optional<SourceRange> loc = c10::nullopt,
      c10::optional<ScopePtr> scope = c10::nullopt);
  
  // note: prefer g.insertConsant(val, loc) which does exactly the same thing
  // this function is only declared/defined here because its implementation is
  // closely related to the implementation of prim::Constant that is also in
  // constants.cpp.
  //
  // returns a c10::nullopt if the IValue kind cannot be inserted as a constant
  TORCH_API c10::optional<Value*> tryInsertConstant(
      Graph& g,
      const IValue& val,
      c10::optional<SourceRange> loc = c10::nullopt,
      c10::optional<ScopePtr> scope = c10::nullopt);
  
  ////////////////////////////////////////////////////////////////////////////////
  // Helper for retrieving constants
  ////////////////////////////////////////////////////////////////////////////////
  
  // attempt to convert a (possibly constant) Value* into an interpreter value
  // (IValue). returns c10::nullopt if the Value* was not constant
  TORCH_API c10::optional<IValue> toIValue(const Value* v);
  
  // if a value is a constant then try to turn into type T using the
  // same rules as the interpreter
  template <typename T>
  c10::optional<T> constant_as(const Value* v) {
    if (auto ivalue = toIValue(v)) {
      return ivalue->to<T>();
    }
    return c10::nullopt;
  }
  } // namespace jit
  } // namespace torch
  