text: // Formatting library for C++ - experimental range support
  //
  // Copyright (c) 2012 - present, Victor Zverovich
  // All rights reserved.
  //
  // For the license information refer to format.h.
  //
  // Copyright (c) 2018 - present, Remotion (Igor Schulz)
  // All Rights Reserved
  // {fmt} support for ranges, containers and types tuple interface.
  
  #ifndef FMT_RANGES_H_
  #define FMT_RANGES_H_
  
  #include <initializer_list>
  #include <type_traits>
  
  #include "format.h"
  
  // output only up to N items from the range.
  #ifndef FMT_RANGE_OUTPUT_LENGTH_LIMIT
  #  define FMT_RANGE_OUTPUT_LENGTH_LIMIT 256
  #endif
  
  FMT_BEGIN_NAMESPACE
  
  template <typename Char> struct formatting_base {
    template <typename ParseContext>
    FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
      return ctx.begin();
    }
  };
  
  template <typename Char, typename Enable = void>
  struct formatting_range : formatting_base<Char> {
    static FMT_CONSTEXPR_DECL const size_t range_length_limit =
        FMT_RANGE_OUTPUT_LENGTH_LIMIT;  // output only up to N items from the
                                        // range.
    Char prefix = '{';
    Char postfix = '}';
  };
  
  template <typename Char, typename Enable = void>
  struct formatting_tuple : formatting_base<Char> {
    Char prefix = '(';
    Char postfix = ')';
  };
  
  namespace detail {
  
  template <typename RangeT, typename OutputIterator>
  OutputIterator copy(const RangeT& range, OutputIterator out) {
    for (auto it = range.begin(), end = range.end(); it != end; ++it)
      *out++ = *it;
    return out;
  }
  
  template <typename OutputIterator>
  OutputIterator copy(const char* str, OutputIterator out) {
    while (*str) *out++ = *str++;
    return out;
  }
  
  template <typename OutputIterator>
  OutputIterator copy(char ch, OutputIterator out) {
    *out++ = ch;
    return out;
  }
  
  template <typename OutputIterator>
  OutputIterator copy(wchar_t ch, OutputIterator out) {
    *out++ = ch;
    return out;
  }
  
  /// Return true value if T has std::string interface, like std::string_view.
  template <typename T> class is_like_std_string {
    template <typename U>
    static auto check(U* p)
        -> decltype((void)p->find('a'), p->length(), (void)p->data(), int());
    template <typename> static void check(...);
  
   public:
    static FMT_CONSTEXPR_DECL const bool value =
        is_string<T>::value || !std::is_void<decltype(check<T>(nullptr))>::value;
  };
  
  template <typename Char>
  struct is_like_std_string<fmt::basic_string_view<Char>> : std::true_type {};
  
  template <typename... Ts> struct conditional_helper {};
  
  template <typename T, typename _ = void> struct is_range_ : std::false_type {};
  
  #if !FMT_MSC_VER || FMT_MSC_VER > 1800
  
  #  define FMT_DECLTYPE_RETURN(val)  \
      ->decltype(val) { return val; } \
      static_assert(                  \
          true, "")  // This makes it so that a semicolon is required after the
                     // macro, which helps clang-format handle the formatting.
  
  // C array overload
  template <typename T, std::size_t N>
  auto range_begin(const T (&arr)[N]) -> const T* {
    return arr;
  }
  template <typename T, std::size_t N>
  auto range_end(const T (&arr)[N]) -> const T* {
    return arr + N;
  }
  
  template <typename T, typename Enable = void>
  struct has_member_fn_begin_end_t : std::false_type {};
  
  template <typename T>
  struct has_member_fn_begin_end_t<T, void_t<decltype(std::declval<T>().begin()),
                                             decltype(std::declval<T>().end())>>
      : std::true_type {};
  
  // Member function overload
  template <typename T>
  auto range_begin(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).begin());
  template <typename T>
  auto range_end(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).end());
  
  // ADL overload. Only participates in overload resolution if member functions
  // are not found.
  template <typename T>
  auto range_begin(T&& rng)
      -> enable_if_t<!has_member_fn_begin_end_t<T&&>::value,
                     decltype(begin(static_cast<T&&>(rng)))> {
    return begin(static_cast<T&&>(rng));
  }
  template <typename T>
  auto range_end(T&& rng) -> enable_if_t<!has_member_fn_begin_end_t<T&&>::value,
                                         decltype(end(static_cast<T&&>(rng)))> {
    return end(static_cast<T&&>(rng));
  }
  
  template <typename T, typename Enable = void>
  struct has_const_begin_end : std::false_type {};
  template <typename T, typename Enable = void>
  struct has_mutable_begin_end : std::false_type {};
  
  template <typename T>
  struct has_const_begin_end<
      T, void_t<decltype(detail::range_begin(
                    std::declval<const remove_cvref_t<T>&>())),
                decltype(detail::range_begin(
                    std::declval<const remove_cvref_t<T>&>()))>>
      : std::true_type {};
  
  template <typename T>
  struct has_mutable_begin_end<
      T, void_t<decltype(detail::range_begin(std::declval<T>())),
                decltype(detail::range_begin(std::declval<T>())),
                enable_if_t<std::is_copy_constructible<T>::value>>>
      : std::true_type {};
  
  template <typename T>
  struct is_range_<T, void>
      : std::integral_constant<bool, (has_const_begin_end<T>::value ||
                                      has_mutable_begin_end<T>::value)> {};
  
  template <typename T, typename Enable = void> struct range_to_view;
  template <typename T>
  struct range_to_view<T, enable_if_t<has_const_begin_end<T>::value>> {
    struct view_t {
      const T* m_range_ptr;
  
      auto begin() const FMT_DECLTYPE_RETURN(detail::range_begin(*m_range_ptr));
      auto end() const FMT_DECLTYPE_RETURN(detail::range_end(*m_range_ptr));
    };
    static auto view(const T& range) -> view_t { return {&range}; }
  };
  
  template <typename T>
  struct range_to_view<T, enable_if_t<!has_const_begin_end<T>::value &&
                                      has_mutable_begin_end<T>::value>> {
    struct view_t {
      T m_range_copy;
  
      auto begin() FMT_DECLTYPE_RETURN(detail::range_begin(m_range_copy));
      auto end() FMT_DECLTYPE_RETURN(detail::range_end(m_range_copy));
    };
    static auto view(const T& range) -> view_t { return {range}; }
  };
  #  undef FMT_DECLTYPE_RETURN
  #endif
  
  /// tuple_size and tuple_element check.
  template <typename T> class is_tuple_like_ {
    template <typename U>
    static auto check(U* p) -> decltype(std::tuple_size<U>::value, int());
    template <typename> static void check(...);
  
   public:
    static FMT_CONSTEXPR_DECL const bool value =
        !std::is_void<decltype(check<T>(nullptr))>::value;
  };
  
  // Check for integer_sequence
  #if defined(__cpp_lib_integer_sequence) || FMT_MSC_VER >= 1900
  template <typename T, T... N>
  using integer_sequence = std::integer_sequence<T, N...>;
  template <size_t... N> using index_sequence = std::index_sequence<N...>;
  template <size_t N> using make_index_sequence = std::make_index_sequence<N>;
  #else
  template <typename T, T... N> struct integer_sequence {
    using value_type = T;
  
    static FMT_CONSTEXPR size_t size() { return sizeof...(N); }
  };
  
  template <size_t... N> using index_sequence = integer_sequence<size_t, N...>;
  
  template <typename T, size_t N, T... Ns>
  struct make_integer_sequence : make_integer_sequence<T, N - 1, N - 1, Ns...> {};
  template <typename T, T... Ns>
  struct make_integer_sequence<T, 0, Ns...> : integer_sequence<T, Ns...> {};
  
  template <size_t N>
  using make_index_sequence = make_integer_sequence<size_t, N>;
  #endif
  
  template <class Tuple, class F, size_t... Is>
  void for_each(index_sequence<Is...>, Tuple&& tup, F&& f) FMT_NOEXCEPT {
    using std::get;
    // using free function get<I>(T) now.
    const int _[] = {0, ((void)f(get<Is>(tup)), 0)...};
    (void)_;  // blocks warnings
  }
  
  template <class T>
  FMT_CONSTEXPR make_index_sequence<std::tuple_size<T>::value> get_indexes(
      T const&) {
    return {};
  }
  
  template <class Tuple, class F> void for_each(Tuple&& tup, F&& f) {
    const auto indexes = get_indexes(tup);
    for_each(indexes, std::forward<Tuple>(tup), std::forward<F>(f));
  }
  
  template <typename Range>
  using value_type =
      remove_cvref_t<decltype(*detail::range_begin(std::declval<Range>()))>;
  
  template <typename OutputIt> OutputIt write_delimiter(OutputIt out) {
    *out++ = ',';
    *out++ = ' ';
    return out;
  }
  
  template <
      typename Char, typename OutputIt, typename Arg,
      FMT_ENABLE_IF(is_like_std_string<typename std::decay<Arg>::type>::value)>
  OutputIt write_range_entry(OutputIt out, const Arg& v) {
    *out++ = '"';
    out = write<Char>(out, v);
    *out++ = '"';
    return out;
  }
  
  template <typename Char, typename OutputIt, typename Arg,
            FMT_ENABLE_IF(std::is_same<Arg, Char>::value)>
  OutputIt write_range_entry(OutputIt out, const Arg v) {
    *out++ = '\'';
    *out++ = v;
    *out++ = '\'';
    return out;
  }
  
  template <
      typename Char, typename OutputIt, typename Arg,
      FMT_ENABLE_IF(!is_like_std_string<typename std::decay<Arg>::type>::value &&
                    !std::is_same<Arg, Char>::value)>
  OutputIt write_range_entry(OutputIt out, const Arg& v) {
    return write<Char>(out, v);
  }
  
  }  // namespace detail
  
  template <typename T> struct is_tuple_like {
    static FMT_CONSTEXPR_DECL const bool value =
        detail::is_tuple_like_<T>::value && !detail::is_range_<T>::value;
  };
  
  template <typename TupleT, typename Char>
  struct formatter<TupleT, Char, enable_if_t<fmt::is_tuple_like<TupleT>::value>> {
   private:
    // C++11 generic lambda for format()
    template <typename FormatContext> struct format_each {
      template <typename T> void operator()(const T& v) {
        if (i > 0) out = detail::write_delimiter(out);
        out = detail::write_range_entry<Char>(out, v);
        ++i;
      }
      formatting_tuple<Char>& formatting;
      size_t& i;
      typename std::add_lvalue_reference<decltype(
          std::declval<FormatContext>().out())>::type out;
    };
  
   public:
    formatting_tuple<Char> formatting;
  
    template <typename ParseContext>
    FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
      return formatting.parse(ctx);
    }
  
    template <typename FormatContext = format_context>
    auto format(const TupleT& values, FormatContext& ctx) -> decltype(ctx.out()) {
      auto out = ctx.out();
      size_t i = 0;
  
      detail::copy(formatting.prefix, out);
      detail::for_each(values, format_each<FormatContext>{formatting, i, out});
      detail::copy(formatting.postfix, out);
  
      return ctx.out();
    }
  };
  
  template <typename T, typename Char> struct is_range {
    static FMT_CONSTEXPR_DECL const bool value =
        detail::is_range_<T>::value && !detail::is_like_std_string<T>::value &&
        !std::is_convertible<T, std::basic_string<Char>>::value &&
        !std::is_constructible<detail::std_string_view<Char>, T>::value;
  };
  
  template <typename T, typename Char>
  struct formatter<
      T, Char,
      enable_if_t<fmt::is_range<T, Char>::value
  // Workaround a bug in MSVC 2017 and earlier.
  #if !FMT_MSC_VER || FMT_MSC_VER >= 1927
                  &&
                  (has_formatter<detail::value_type<T>, format_context>::value ||
                   detail::has_fallback_formatter<detail::value_type<T>,
                                                  format_context>::value)
  #endif
                  >> {
    formatting_range<Char> formatting;
  
    template <typename ParseContext>
    FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
      return formatting.parse(ctx);
    }
  
    template <typename FormatContext>
    typename FormatContext::iterator format(const T& values, FormatContext& ctx) {
      auto out = detail::copy(formatting.prefix, ctx.out());
      size_t i = 0;
      auto view = detail::range_to_view<T>::view(values);
      auto it = view.begin();
      auto end = view.end();
      for (; it != end; ++it) {
        if (i > 0) out = detail::write_delimiter(out);
        out = detail::write_range_entry<Char>(out, *it);
        if (++i > formatting.range_length_limit) {
          out = format_to(out, FMT_STRING("{}"), " ... <other elements>");
          break;
        }
      }
      return detail::copy(formatting.postfix, out);
    }
  };
  
  template <typename Char, typename... T> struct tuple_arg_join : detail::view {
    const std::tuple<T...>& tuple;
    basic_string_view<Char> sep;
  
    tuple_arg_join(const std::tuple<T...>& t, basic_string_view<Char> s)
        : tuple(t), sep{s} {}
  };
  
  template <typename Char, typename... T>
  struct formatter<tuple_arg_join<Char, T...>, Char> {
    template <typename ParseContext>
    FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
      return ctx.begin();
    }
  
    template <typename FormatContext>
    typename FormatContext::iterator format(
        const tuple_arg_join<Char, T...>& value, FormatContext& ctx) {
      return format(value, ctx, detail::make_index_sequence<sizeof...(T)>{});
    }
  
   private:
    template <typename FormatContext, size_t... N>
    typename FormatContext::iterator format(
        const tuple_arg_join<Char, T...>& value, FormatContext& ctx,
        detail::index_sequence<N...>) {
      return format_args(value, ctx, std::get<N>(value.tuple)...);
    }
  
    template <typename FormatContext>
    typename FormatContext::iterator format_args(
        const tuple_arg_join<Char, T...>&, FormatContext& ctx) {
      // NOTE: for compilers that support C++17, this empty function instantiation
      // can be replaced with a constexpr branch in the variadic overload.
      return ctx.out();
    }
  
    template <typename FormatContext, typename Arg, typename... Args>
    typename FormatContext::iterator format_args(
        const tuple_arg_join<Char, T...>& value, FormatContext& ctx,
        const Arg& arg, const Args&... args) {
      using base = formatter<typename std::decay<Arg>::type, Char>;
      auto out = ctx.out();
      out = base{}.format(arg, ctx);
      if (sizeof...(Args) > 0) {
        out = std::copy(value.sep.begin(), value.sep.end(), out);
        ctx.advance_to(out);
        return format_args(value, ctx, args...);
      }
      return out;
    }
  };
  
  FMT_MODULE_EXPORT_BEGIN
  
  /**
    \rst
    Returns an object that formats `tuple` with elements separated by `sep`.
  
    **Example**::
  
      std::tuple<int, char> t = {1, 'a'};
      fmt::print("{}", fmt::join(t, ", "));
      // Output: "1, a"
    \endrst
   */
  template <typename... T>
  FMT_CONSTEXPR tuple_arg_join<char, T...> join(const std::tuple<T...>& tuple,
                                                string_view sep) {
    return {tuple, sep};
  }
  
  template <typename... T>
  FMT_CONSTEXPR tuple_arg_join<wchar_t, T...> join(const std::tuple<T...>& tuple,
                                                   wstring_view sep) {
    return {tuple, sep};
  }
  
  /**
    \rst
    Returns an object that formats `initializer_list` with elements separated by
    `sep`.
  
    **Example**::
  
      fmt::print("{}", fmt::join({1, 2, 3}, ", "));
      // Output: "1, 2, 3"
    \endrst
   */
  template <typename T>
  arg_join<const T*, const T*, char> join(std::initializer_list<T> list,
                                          string_view sep) {
    return join(std::begin(list), std::end(list), sep);
  }
  
  template <typename T>
  arg_join<const T*, const T*, wchar_t> join(std::initializer_list<T> list,
                                             wstring_view sep) {
    return join(std::begin(list), std::end(list), sep);
  }
  
  FMT_MODULE_EXPORT_END
  FMT_END_NAMESPACE
  
  #endif  // FMT_RANGES_H_
  