blame: source/misc/embedded_libs/fmt-11.0.2/include/fmt/compile.h

// Formatting library for C++ - experimental format string compilation

//

// Copyright (c) 2012 - present, Victor Zverovich and fmt contributors

// All rights reserved.

//

// For the license information refer to format.h.

#ifndef FMT_COMPILE_H_

#define FMT_COMPILE_H_

#ifndef FMT_MODULE

#  include <iterator>  // std::back_inserter

#endif

#include "format.h"

FMT_BEGIN_NAMESPACE

// A compile-time string which is compiled into fast formatting code.

FMT_EXPORT class compiled_string {};

namespace detail {

template <typename T, typename InputIt>

FMT_CONSTEXPR inline auto copy(InputIt begin, InputIt end, counting_iterator it)

    -> counting_iterator {

  return it + (end - begin);

}

template <typename S>

struct is_compiled_string : std::is_base_of<compiled_string, S> {};

/**

 * Converts a string literal `s` into a format string that will be parsed at

 * compile time and converted into efficient formatting code. Requires C++17

 * `constexpr if` compiler support.

 *

 * **Example**:

 *

 *     // Converts 42 into std::string using the most efficient method and no

 *     // runtime format string processing.

 *     std::string s = fmt::format(FMT_COMPILE("{}"), 42);

 */

#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)

#  define FMT_COMPILE(s) FMT_STRING_IMPL(s, fmt::compiled_string, explicit)

#else

#  define FMT_COMPILE(s) FMT_STRING(s)

#endif

#if FMT_USE_NONTYPE_TEMPLATE_ARGS

template <typename Char, size_t N,

          fmt::detail_exported::fixed_string<Char, N> Str>

struct udl_compiled_string : compiled_string {

  using char_type = Char;

  explicit constexpr operator basic_string_view<char_type>() const {

    return {Str.data, N - 1};

  }

};

#endif

template <typename T, typename... Tail>

auto first(const T& value, const Tail&...) -> const T& {

  return value;

}

#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)

template <typename... Args> struct type_list {};

// Returns a reference to the argument at index N from [first, rest...].

template <int N, typename T, typename... Args>

constexpr const auto& get([[maybe_unused]] const T& first,

                          [[maybe_unused]] const Args&... rest) {

  static_assert(N < 1 + sizeof...(Args), "index is out of bounds");

  if constexpr (N == 0)

    return first;

  else

    return detail::get<N - 1>(rest...);

}

template <typename Char, typename... Args>

constexpr int get_arg_index_by_name(basic_string_view<Char> name,

                                    type_list<Args...>) {

  return get_arg_index_by_name<Args...>(name);

}

template <int N, typename> struct get_type_impl;

template <int N, typename... Args> struct get_type_impl<N, type_list<Args...>> {

  using type =

      remove_cvref_t<decltype(detail::get<N>(std::declval<Args>()...))>;

};

template <int N, typename T>

using get_type = typename get_type_impl<N, T>::type;

template <typename T> struct is_compiled_format : std::false_type {};

template <typename Char> struct text {

  basic_string_view<Char> data;

  using char_type = Char;

  template <typename OutputIt, typename... Args>

  constexpr OutputIt format(OutputIt out, const Args&...) const {

    return write<Char>(out, data);

  }

};

template <typename Char>

struct is_compiled_format<text<Char>> : std::true_type {};

template <typename Char>

constexpr text<Char> make_text(basic_string_view<Char> s, size_t pos,

                               size_t size) {

  return {{&s[pos], size}};

}

template <typename Char> struct code_unit {

  Char value;

  using char_type = Char;

  template <typename OutputIt, typename... Args>

  constexpr OutputIt format(OutputIt out, const Args&...) const {

    *out++ = value;

    return out;

  }

};

// This ensures that the argument type is convertible to `const T&`.

template <typename T, int N, typename... Args>

constexpr const T& get_arg_checked(const Args&... args) {

  const auto& arg = detail::get<N>(args...);

  if constexpr (detail::is_named_arg<remove_cvref_t<decltype(arg)>>()) {

    return arg.value;

  } else {

    return arg;

  }

}

template <typename Char>

struct is_compiled_format<code_unit<Char>> : std::true_type {};

// A replacement field that refers to argument N.

template <typename Char, typename T, int N> struct field {

  using char_type = Char;

  template <typename OutputIt, typename... Args>

  constexpr OutputIt format(OutputIt out, const Args&... args) const {

    const T& arg = get_arg_checked<T, N>(args...);

    if constexpr (std::is_convertible<T, basic_string_view<Char>>::value) {

      auto s = basic_string_view<Char>(arg);

      return copy<Char>(s.begin(), s.end(), out);

    }

    return write<Char>(out, arg);

  }

};

template <typename Char, typename T, int N>

struct is_compiled_format<field<Char, T, N>> : std::true_type {};

// A replacement field that refers to argument with name.

template <typename Char> struct runtime_named_field {

  using char_type = Char;

  basic_string_view<Char> name;

  template <typename OutputIt, typename T>

  constexpr static bool try_format_argument(

      OutputIt& out,

      // [[maybe_unused]] due to unused-but-set-parameter warning in GCC 7,8,9

      [[maybe_unused]] basic_string_view<Char> arg_name, const T& arg) {

    if constexpr (is_named_arg<typename std::remove_cv<T>::type>::value) {

      if (arg_name == arg.name) {

        out = write<Char>(out, arg.value);

        return true;

      }

    }

    return false;

  }

  template <typename OutputIt, typename... Args>

  constexpr OutputIt format(OutputIt out, const Args&... args) const {

    bool found = (try_format_argument(out, name, args) || ...);

    if (!found) {

      FMT_THROW(format_error("argument with specified name is not found"));

    }

    return out;

  }

};

template <typename Char>

struct is_compiled_format<runtime_named_field<Char>> : std::true_type {};

// A replacement field that refers to argument N and has format specifiers.

template <typename Char, typename T, int N> struct spec_field {

  using char_type = Char;

  formatter<T, Char> fmt;

  template <typename OutputIt, typename... Args>

  constexpr FMT_INLINE OutputIt format(OutputIt out,

                                       const Args&... args) const {

    const auto& vargs =

        fmt::make_format_args<basic_format_context<OutputIt, Char>>(args...);

    basic_format_context<OutputIt, Char> ctx(out, vargs);

    return fmt.format(get_arg_checked<T, N>(args...), ctx);

  }

};

template <typename Char, typename T, int N>

struct is_compiled_format<spec_field<Char, T, N>> : std::true_type {};

template <typename L, typename R> struct concat {

  L lhs;

  R rhs;

  using char_type = typename L::char_type;

  template <typename OutputIt, typename... Args>

  constexpr OutputIt format(OutputIt out, const Args&... args) const {

    out = lhs.format(out, args...);

    return rhs.format(out, args...);

  }

};

template <typename L, typename R>

struct is_compiled_format<concat<L, R>> : std::true_type {};

template <typename L, typename R>

constexpr concat<L, R> make_concat(L lhs, R rhs) {

  return {lhs, rhs};

}

struct unknown_format {};

template <typename Char>

constexpr size_t parse_text(basic_string_view<Char> str, size_t pos) {

  for (size_t size = str.size(); pos != size; ++pos) {

    if (str[pos] == '{' || str[pos] == '}') break;

  }

  return pos;

}

template <typename Args, size_t POS, int ID, typename S>

constexpr auto compile_format_string(S fmt);

template <typename Args, size_t POS, int ID, typename T, typename S>

constexpr auto parse_tail(T head, S fmt) {

  if constexpr (POS != basic_string_view<typename S::char_type>(fmt).size()) {

    constexpr auto tail = compile_format_string<Args, POS, ID>(fmt);

    if constexpr (std::is_same<remove_cvref_t<decltype(tail)>,

                               unknown_format>())

      return tail;

    else

      return make_concat(head, tail);

  } else {

    return head;

  }

}

template <typename T, typename Char> struct parse_specs_result {

  formatter<T, Char> fmt;

  size_t end;

  int next_arg_id;

};

enum { manual_indexing_id = -1 };

template <typename T, typename Char>

constexpr parse_specs_result<T, Char> parse_specs(basic_string_view<Char> str,

                                                  size_t pos, int next_arg_id) {

  str.remove_prefix(pos);

  auto ctx =

      compile_parse_context<Char>(str, max_value<int>(), nullptr, next_arg_id);

  auto f = formatter<T, Char>();

  auto end = f.parse(ctx);

  return {f, pos + fmt::detail::to_unsigned(end - str.data()),

          next_arg_id == 0 ? manual_indexing_id : ctx.next_arg_id()};

}

template <typename Char> struct arg_id_handler {

  arg_ref<Char> arg_id;

  constexpr int on_auto() {

    FMT_ASSERT(false, "handler cannot be used with automatic indexing");

    return 0;

  }

  constexpr int on_index(int id) {

    arg_id = arg_ref<Char>(id);

    return 0;

  }

  constexpr int on_name(basic_string_view<Char> id) {

    arg_id = arg_ref<Char>(id);

    return 0;

  }

};

template <typename Char> struct parse_arg_id_result {

  arg_ref<Char> arg_id;

  const Char* arg_id_end;

};

template <int ID, typename Char>

constexpr auto parse_arg_id(const Char* begin, const Char* end) {

  auto handler = arg_id_handler<Char>{arg_ref<Char>{}};

  auto arg_id_end = parse_arg_id(begin, end, handler);

  return parse_arg_id_result<Char>{handler.arg_id, arg_id_end};

}

template <typename T, typename Enable = void> struct field_type {

  using type = remove_cvref_t<T>;

};

template <typename T>

struct field_type<T, enable_if_t<detail::is_named_arg<T>::value>> {

  using type = remove_cvref_t<decltype(T::value)>;

};

template <typename T, typename Args, size_t END_POS, int ARG_INDEX, int NEXT_ID,

          typename S>

constexpr auto parse_replacement_field_then_tail(S fmt) {

  using char_type = typename S::char_type;

  constexpr auto str = basic_string_view<char_type>(fmt);

  constexpr char_type c = END_POS != str.size() ? str[END_POS] : char_type();

  if constexpr (c == '}') {

    return parse_tail<Args, END_POS + 1, NEXT_ID>(

        field<char_type, typename field_type<T>::type, ARG_INDEX>(), fmt);

  } else if constexpr (c != ':') {

    FMT_THROW(format_error("expected ':'"));

  } else {

    constexpr auto result = parse_specs<typename field_type<T>::type>(

        str, END_POS + 1, NEXT_ID == manual_indexing_id ? 0 : NEXT_ID);

    if constexpr (result.end >= str.size() || str[result.end] != '}') {

      FMT_THROW(format_error("expected '}'"));

      return 0;

    } else {

      return parse_tail<Args, result.end + 1, result.next_arg_id>(

          spec_field<char_type, typename field_type<T>::type, ARG_INDEX>{

              result.fmt},

          fmt);

    }

  }

}

// Compiles a non-empty format string and returns the compiled representation

// or unknown_format() on unrecognized input.

template <typename Args, size_t POS, int ID, typename S>

constexpr auto compile_format_string(S fmt) {

  using char_type = typename S::char_type;

  constexpr auto str = basic_string_view<char_type>(fmt);

  if constexpr (str[POS] == '{') {

    if constexpr (POS + 1 == str.size())

      FMT_THROW(format_error("unmatched '{' in format string"));

    if constexpr (str[POS + 1] == '{') {

      return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), fmt);

    } else if constexpr (str[POS + 1] == '}' || str[POS + 1] == ':') {

      static_assert(ID != manual_indexing_id,

                    "cannot switch from manual to automatic argument indexing");

      constexpr auto next_id =

          ID != manual_indexing_id ? ID + 1 : manual_indexing_id;

      return parse_replacement_field_then_tail<get_type<ID, Args>, Args,

                                               POS + 1, ID, next_id>(fmt);

    } else {

      constexpr auto arg_id_result =

          parse_arg_id<ID>(str.data() + POS + 1, str.data() + str.size());

      constexpr auto arg_id_end_pos = arg_id_result.arg_id_end - str.data();

      constexpr char_type c =

          arg_id_end_pos != str.size() ? str[arg_id_end_pos] : char_type();

      static_assert(c == '}' || c == ':', "missing '}' in format string");

      if constexpr (arg_id_result.arg_id.kind == arg_id_kind::index) {

        static_assert(

            ID == manual_indexing_id || ID == 0,

            "cannot switch from automatic to manual argument indexing");

        constexpr auto arg_index = arg_id_result.arg_id.val.index;

        return parse_replacement_field_then_tail<get_type<arg_index, Args>,

                                                 Args, arg_id_end_pos,

                                                 arg_index, manual_indexing_id>(

            fmt);

      } else if constexpr (arg_id_result.arg_id.kind == arg_id_kind::name) {

        constexpr auto arg_index =

            get_arg_index_by_name(arg_id_result.arg_id.val.name, Args{});

        if constexpr (arg_index >= 0) {

          constexpr auto next_id =

              ID != manual_indexing_id ? ID + 1 : manual_indexing_id;

          return parse_replacement_field_then_tail<

              decltype(get_type<arg_index, Args>::value), Args, arg_id_end_pos,

              arg_index, next_id>(fmt);

        } else if constexpr (c == '}') {

          return parse_tail<Args, arg_id_end_pos + 1, ID>(

              runtime_named_field<char_type>{arg_id_result.arg_id.val.name},

              fmt);

        } else if constexpr (c == ':') {

          return unknown_format();  // no type info for specs parsing

        }

      }

    }

  } else if constexpr (str[POS] == '}') {

    if constexpr (POS + 1 == str.size())

      FMT_THROW(format_error("unmatched '}' in format string"));

    return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), fmt);

  } else {

    constexpr auto end = parse_text(str, POS + 1);

    if constexpr (end - POS > 1) {

      return parse_tail<Args, end, ID>(make_text(str, POS, end - POS), fmt);

    } else {

      return parse_tail<Args, end, ID>(code_unit<char_type>{str[POS]}, fmt);

    }

  }

}

template <typename... Args, typename S,

          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>

constexpr auto compile(S fmt) {

  constexpr auto str = basic_string_view<typename S::char_type>(fmt);

  if constexpr (str.size() == 0) {

    return detail::make_text(str, 0, 0);

  } else {

    constexpr auto result =

        detail::compile_format_string<detail::type_list<Args...>, 0, 0>(fmt);

    return result;

  }

}

#endif  // defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)

}  // namespace detail

FMT_BEGIN_EXPORT

#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)

template <typename CompiledFormat, typename... Args,

          typename Char = typename CompiledFormat::char_type,

          FMT_ENABLE_IF(detail::is_compiled_format<CompiledFormat>::value)>

FMT_INLINE std::basic_string<Char> format(const CompiledFormat& cf,

                                          const Args&... args) {

  auto s = std::basic_string<Char>();

  cf.format(std::back_inserter(s), args...);

  return s;

}

template <typename OutputIt, typename CompiledFormat, typename... Args,

          FMT_ENABLE_IF(detail::is_compiled_format<CompiledFormat>::value)>

constexpr FMT_INLINE OutputIt format_to(OutputIt out, const CompiledFormat& cf,

                                        const Args&... args) {

  return cf.format(out, args...);

}

template <typename S, typename... Args,

          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>

FMT_INLINE std::basic_string<typename S::char_type> format(const S&,

                                                           Args&&... args) {

  if constexpr (std::is_same<typename S::char_type, char>::value) {

    constexpr auto str = basic_string_view<typename S::char_type>(S());

    if constexpr (str.size() == 2 && str[0] == '{' && str[1] == '}') {

      const auto& first = detail::first(args...);

      if constexpr (detail::is_named_arg<

                        remove_cvref_t<decltype(first)>>::value) {

        return fmt::to_string(first.value);

      } else {

        return fmt::to_string(first);

      }

    }

  }

  constexpr auto compiled = detail::compile<Args...>(S());

  if constexpr (std::is_same<remove_cvref_t<decltype(compiled)>,

                             detail::unknown_format>()) {

    return fmt::format(

        static_cast<basic_string_view<typename S::char_type>>(S()),

        std::forward<Args>(args)...);

  } else {

    return fmt::format(compiled, std::forward<Args>(args)...);

  }

}

template <typename OutputIt, typename S, typename... Args,

          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>

FMT_CONSTEXPR OutputIt format_to(OutputIt out, const S&, Args&&... args) {

  constexpr auto compiled = detail::compile<Args...>(S());

  if constexpr (std::is_same<remove_cvref_t<decltype(compiled)>,

                             detail::unknown_format>()) {

    return fmt::format_to(

        out, static_cast<basic_string_view<typename S::char_type>>(S()),

        std::forward<Args>(args)...);

  } else {

    return fmt::format_to(out, compiled, std::forward<Args>(args)...);

  }

}

#endif

template <typename OutputIt, typename S, typename... Args,

          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>

auto format_to_n(OutputIt out, size_t n, const S& fmt, Args&&... args)

    -> format_to_n_result<OutputIt> {

  using traits = detail::fixed_buffer_traits;

  auto buf = detail::iterator_buffer<OutputIt, char, traits>(out, n);

  fmt::format_to(std::back_inserter(buf), fmt, std::forward<Args>(args)...);

  return {buf.out(), buf.count()};

}

template <typename S, typename... Args,

          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>

FMT_CONSTEXPR20 auto formatted_size(const S& fmt, const Args&... args)

    -> size_t {

  return fmt::format_to(detail::counting_iterator(), fmt, args...).count();

}

template <typename S, typename... Args,

          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>

void print(std::FILE* f, const S& fmt, const Args&... args) {

  memory_buffer buffer;

  fmt::format_to(std::back_inserter(buffer), fmt, args...);

  detail::print(f, {buffer.data(), buffer.size()});

}

template <typename S, typename... Args,

          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>

void print(const S& fmt, const Args&... args) {

  print(stdout, fmt, args...);

}

#if FMT_USE_NONTYPE_TEMPLATE_ARGS

inline namespace literals {

template <detail_exported::fixed_string Str> constexpr auto operator""_cf() {

  using char_t = remove_cvref_t<decltype(Str.data[0])>;

  return detail::udl_compiled_string<char_t, sizeof(Str.data) / sizeof(char_t),

                                     Str>();

}

}  // namespace literals

#endif

FMT_END_EXPORT

FMT_END_NAMESPACE

#endif  // FMT_COMPILE_H_