blame: source/misc/embedded_libs/fmt-8.1.1/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_

#include "format.h"

FMT_BEGIN_NAMESPACE

namespace detail {

// An output iterator that counts the number of objects written to it and

// discards them.

class counting_iterator {

 private:

  size_t count_;

 public:

  using iterator_category = std::output_iterator_tag;

  using difference_type = std::ptrdiff_t;

  using pointer = void;

  using reference = void;

  using _Unchecked_type = counting_iterator;  // Mark iterator as checked.

  struct value_type {

    template <typename T> void operator=(const T&) {}

  };

  counting_iterator() : count_(0) {}

  size_t count() const { return count_; }

  counting_iterator& operator++() {

    ++count_;

    return *this;

  }

  counting_iterator operator++(int) {

    auto it = *this;

    ++*this;

    return it;

  }

  friend counting_iterator operator+(counting_iterator it, difference_type n) {

    it.count_ += static_cast<size_t>(n);

    return it;

  }

  value_type operator*() const { return {}; }

};

template <typename Char, typename InputIt>

inline counting_iterator copy_str(InputIt begin, InputIt end,

                                  counting_iterator it) {

  return it + (end - begin);

}

template <typename OutputIt> class truncating_iterator_base {

 protected:

  OutputIt out_;

  size_t limit_;

  size_t count_ = 0;

  truncating_iterator_base() : out_(), limit_(0) {}

  truncating_iterator_base(OutputIt out, size_t limit)

      : out_(out), limit_(limit) {}

 public:

  using iterator_category = std::output_iterator_tag;

  using value_type = typename std::iterator_traits<OutputIt>::value_type;

  using difference_type = std::ptrdiff_t;

  using pointer = void;

  using reference = void;

  using _Unchecked_type =

      truncating_iterator_base;  // Mark iterator as checked.

  OutputIt base() const { return out_; }

  size_t count() const { return count_; }

};

// An output iterator that truncates the output and counts the number of objects

// written to it.

template <typename OutputIt,

          typename Enable = typename std::is_void<

              typename std::iterator_traits<OutputIt>::value_type>::type>

class truncating_iterator;

template <typename OutputIt>

class truncating_iterator<OutputIt, std::false_type>

    : public truncating_iterator_base<OutputIt> {

  mutable typename truncating_iterator_base<OutputIt>::value_type blackhole_;

 public:

  using value_type = typename truncating_iterator_base<OutputIt>::value_type;

  truncating_iterator() = default;

  truncating_iterator(OutputIt out, size_t limit)

      : truncating_iterator_base<OutputIt>(out, limit) {}

  truncating_iterator& operator++() {

    if (this->count_++ < this->limit_) ++this->out_;

    return *this;

  }

  truncating_iterator operator++(int) {

    auto it = *this;

    ++*this;

    return it;

  }

  value_type& operator*() const {

    return this->count_ < this->limit_ ? *this->out_ : blackhole_;

  }

};

template <typename OutputIt>

class truncating_iterator<OutputIt, std::true_type>

    : public truncating_iterator_base<OutputIt> {

 public:

  truncating_iterator() = default;

  truncating_iterator(OutputIt out, size_t limit)

      : truncating_iterator_base<OutputIt>(out, limit) {}

  template <typename T> truncating_iterator& operator=(T val) {

    if (this->count_++ < this->limit_) *this->out_++ = val;

    return *this;

  }

  truncating_iterator& operator++() { return *this; }

  truncating_iterator& operator++(int) { return *this; }

  truncating_iterator& operator*() { return *this; }

};

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

class compiled_string {};

template <typename S>

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

/**

  \rst

  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);

  \endrst

 */

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

#  define FMT_COMPILE(s) \

    FMT_STRING_IMPL(s, fmt::detail::compiled_string, explicit)

#else

#  define FMT_COMPILE(s) FMT_STRING(s)

#endif

#if FMT_USE_NONTYPE_TEMPLATE_PARAMETERS

template <typename Char, size_t N,

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

struct udl_compiled_string : compiled_string {

  using char_type = Char;

  constexpr operator basic_string_view<char_type>() const {

    return {Str.data, N - 1};

  }

};

#endif

template <typename T, typename... Tail>

const T& first(const T& value, const Tail&...) {

  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 {

    return write<Char>(out, value);

  }

};

// 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 {

    return write<Char>(out, get_arg_checked<T, N>(args...));

  }

};

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 format_str);

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

constexpr auto parse_tail(T head, S format_str) {

  if constexpr (POS !=

                basic_string_view<typename S::char_type>(format_str).size()) {

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

    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;

};

constexpr int 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 = basic_format_parse_context<Char>(str, {}, next_arg_id);

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

  auto end = f.parse(ctx);

  return {f, pos + fmt::detail::to_unsigned(end - str.data()) + 1,

          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 operator()() {

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

    return 0;

  }

  constexpr int operator()(int id) {

    arg_id = arg_ref<Char>(id);

    return 0;

  }

  constexpr int operator()(basic_string_view<Char> id) {

    arg_id = arg_ref<Char>(id);

    return 0;

  }

  constexpr void on_error(const char* message) {

    FMT_THROW(format_error(message));

  }

};

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 format_str) {

  using char_type = typename S::char_type;

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

  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>(),

        format_str);

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

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

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

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

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

            result.fmt},

        format_str);

  }

}

// 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 format_str) {

  using char_type = typename S::char_type;

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

  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), format_str);

    } 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>(

          format_str);

    } 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>(

            format_str);

      } 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 != invalid_arg_index) {

          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>(format_str);

        } 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},

                format_str);

          } 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), format_str);

  } 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),

                                       format_str);

    } else {

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

                                       format_str);

    }

  }

}

template <typename... Args, typename S,

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

constexpr auto compile(S format_str) {

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

  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>(

            format_str);

    return result;

  }

}

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

}  // namespace detail

FMT_MODULE_EXPORT_BEGIN

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

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

  } else {

    return 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 format_to(out,

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

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

  } else {

    return 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)>

format_to_n_result<OutputIt> format_to_n(OutputIt out, size_t n,

                                         const S& format_str, Args&&... args) {

  auto it = format_to(detail::truncating_iterator<OutputIt>(out, n), format_str,

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

  return {it.base(), it.count()};

}

template <typename S, typename... Args,

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

size_t formatted_size(const S& format_str, const Args&... args) {

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

}

template <typename S, typename... Args,

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

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

  memory_buffer buffer;

  format_to(std::back_inserter(buffer), format_str, 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& format_str, const Args&... args) {

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

}

#if FMT_USE_NONTYPE_TEMPLATE_PARAMETERS

inline namespace literals {

template <detail_exported::fixed_string Str>

constexpr detail::udl_compiled_string<

    remove_cvref_t<decltype(Str.data[0])>,

    sizeof(Str.data) / sizeof(decltype(Str.data[0])), Str>

operator""_cf() {

  return {};

}

}  // namespace literals

#endif

FMT_MODULE_EXPORT_END

FMT_END_NAMESPACE

#endif  // FMT_COMPILE_H_