1// <format> Formatting -*- C++ -*-
3// Copyright The GNU Toolchain Authors.
5// This file is part of the GNU ISO C++ Library. This library is free
6// software; you can redistribute it and/or modify it under the
7// terms of the GNU General Public License as published by the
8// Free Software Foundation; either version 3, or (at your option)
11// This library is distributed in the hope that it will be useful,
12// but WITHOUT ANY WARRANTY; without even the implied warranty of
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14// GNU General Public License for more details.
16// Under Section 7 of GPL version 3, you are granted additional
17// permissions described in the GCC Runtime Library Exception, version
18// 3.1, as published by the Free Software Foundation.
20// You should have received a copy of the GNU General Public License and
21// a copy of the GCC Runtime Library Exception along with this program;
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
23// <http://www.gnu.org/licenses/>.
25/** @file include/format
26 * This is a Standard C++ Library header.
29#ifndef _GLIBCXX_FORMAT
30#define _GLIBCXX_FORMAT 1
32#pragma GCC system_header
34#include <bits/requires_hosted.h> // for std::string
36#define __glibcxx_want_format
37#define __glibcxx_want_format_ranges
38#define __glibcxx_want_format_uchar
39#include <bits/version.h>
41#ifdef __cpp_lib_format // C++ >= 20 && HOSTED
52#include <variant> // monostate (TODO: move to bits/utility.h?)
53#include <bits/ranges_base.h> // input_range, range_reference_t
54#include <bits/ranges_util.h> // subrange
55#include <bits/ranges_algobase.h> // ranges::copy
56#include <bits/stl_iterator.h> // back_insert_iterator
57#include <bits/stl_pair.h> // __is_pair
58#include <bits/unicode.h> // __is_scalar_value, _Utf_view, etc.
59#include <bits/utility.h> // tuple_size_v
60#include <ext/numeric_traits.h> // __int_traits
62#if !__has_builtin(__builtin_toupper)
66namespace std _GLIBCXX_VISIBILITY(default)
68_GLIBCXX_BEGIN_NAMESPACE_VERSION
70 // [format.context], class template basic_format_context
71 template<typename _Out, typename _CharT> class basic_format_context;
73 // [format.fmt.string], class template basic_format_string
74 template<typename _CharT, typename... _Args> struct basic_format_string;
79 // Type-erased character sink.
80 template<typename _CharT> class _Sink;
81 // Output iterator that writes to a type-erase character sink.
82 template<typename _CharT>
85 template<typename _CharT>
86 using __format_context = basic_format_context<_Sink_iter<_CharT>, _CharT>;
88 template<typename _CharT>
89 struct _Runtime_format_string
91 [[__gnu__::__always_inline__]]
92 _Runtime_format_string(basic_string_view<_CharT> __s) noexcept
95 _Runtime_format_string(const _Runtime_format_string&) = delete;
96 void operator=(const _Runtime_format_string&) = delete;
99 basic_string_view<_CharT> _M_str;
101 template<typename, typename...> friend struct std::basic_format_string;
103} // namespace __format
106 using format_context = __format::__format_context<char>;
107#ifdef _GLIBCXX_USE_WCHAR_T
108 using wformat_context = __format::__format_context<wchar_t>;
111 // [format.args], class template basic_format_args
112 template<typename _Context> class basic_format_args;
113 using format_args = basic_format_args<format_context>;
114#ifdef _GLIBCXX_USE_WCHAR_T
115 using wformat_args = basic_format_args<wformat_context>;
118 // [format.arguments], arguments
119 // [format.arg], class template basic_format_arg
120 template<typename _Context>
121 class basic_format_arg;
123 /** A compile-time checked format string for the specified argument types.
125 * @since C++23 but available as an extension in C++20.
127 template<typename _CharT, typename... _Args>
128 struct basic_format_string
130 template<typename _Tp>
131 requires convertible_to<const _Tp&, basic_string_view<_CharT>>
133 basic_format_string(const _Tp& __s);
135 [[__gnu__::__always_inline__]]
136 basic_format_string(__format::_Runtime_format_string<_CharT> __s) noexcept
140 [[__gnu__::__always_inline__]]
141 constexpr basic_string_view<_CharT>
146 basic_string_view<_CharT> _M_str;
149 template<typename... _Args>
150 using format_string = basic_format_string<char, type_identity_t<_Args>...>;
152#ifdef _GLIBCXX_USE_WCHAR_T
153 template<typename... _Args>
155 = basic_format_string<wchar_t, type_identity_t<_Args>...>;
158#if __cplusplus > 202302L
159 [[__gnu__::__always_inline__]]
160 inline __format::_Runtime_format_string<char>
161 runtime_format(string_view __fmt) noexcept
164#ifdef _GLIBCXX_USE_WCHAR_T
165 [[__gnu__::__always_inline__]]
166 inline __format::_Runtime_format_string<wchar_t>
167 runtime_format(wstring_view __fmt) noexcept
172 // [format.formatter], formatter
174 /// The primary template of std::formatter is disabled.
175 template<typename _Tp, typename _CharT = char>
178 formatter() = delete; // No std::formatter specialization for this type.
179 formatter(const formatter&) = delete;
180 formatter& operator=(const formatter&) = delete;
183 // [format.error], class format_error
184 class format_error : public runtime_error
187 explicit format_error(const string& __what) : runtime_error(__what) { }
188 explicit format_error(const char* __what) : runtime_error(__what) { }
191 /// @cond undocumented
194 __throw_format_error(const char* __what)
195 { _GLIBCXX_THROW_OR_ABORT(format_error(__what)); }
199 // XXX use named functions for each constexpr error?
203 __unmatched_left_brace_in_format_string()
204 { __throw_format_error("format error: unmatched '{' in format string"); }
208 __unmatched_right_brace_in_format_string()
209 { __throw_format_error("format error: unmatched '}' in format string"); }
213 __conflicting_indexing_in_format_string()
214 { __throw_format_error("format error: conflicting indexing style in format string"); }
218 __invalid_arg_id_in_format_string()
219 { __throw_format_error("format error: invalid arg-id in format string"); }
223 __failed_to_parse_format_spec()
224 { __throw_format_error("format error: failed to parse format-spec"); }
225} // namespace __format
228 // [format.parse.ctx], class template basic_format_parse_context
229 template<typename _CharT> class basic_format_parse_context;
230 using format_parse_context = basic_format_parse_context<char>;
231#ifdef _GLIBCXX_USE_WCHAR_T
232 using wformat_parse_context = basic_format_parse_context<wchar_t>;
235 template<typename _CharT>
236 class basic_format_parse_context
239 using char_type = _CharT;
240 using const_iterator = typename basic_string_view<_CharT>::const_iterator;
241 using iterator = const_iterator;
244 basic_format_parse_context(basic_string_view<_CharT> __fmt,
245 size_t __num_args = 0) noexcept
246 : _M_begin(__fmt.begin()), _M_end(__fmt.end()), _M_num_args(__num_args)
249 basic_format_parse_context(const basic_format_parse_context&) = delete;
250 void operator=(const basic_format_parse_context&) = delete;
252 constexpr const_iterator begin() const noexcept { return _M_begin; }
253 constexpr const_iterator end() const noexcept { return _M_end; }
256 advance_to(const_iterator __it) noexcept
262 if (_M_indexing == _Manual)
263 __format::__conflicting_indexing_in_format_string();
266 // _GLIBCXX_RESOLVE_LIB_DEFECTS
267 // 3825. Missing compile-time argument id check in next_arg_id
268 if (std::is_constant_evaluated())
269 if (_M_next_arg_id == _M_num_args)
270 __format::__invalid_arg_id_in_format_string();
271 return _M_next_arg_id++;
275 check_arg_id(size_t __id)
277 if (_M_indexing == _Auto)
278 __format::__conflicting_indexing_in_format_string();
279 _M_indexing = _Manual;
281 if (std::is_constant_evaluated())
282 if (__id >= _M_num_args)
283 __format::__invalid_arg_id_in_format_string();
289 enum _Indexing { _Unknown, _Manual, _Auto };
290 _Indexing _M_indexing = _Unknown;
291 size_t _M_next_arg_id = 0;
295/// @cond undocumented
296 template<typename _Tp, template<typename...> class _Class>
297 static constexpr bool __is_specialization_of = false;
298 template<template<typename...> class _Class, typename... _Args>
299 static constexpr bool __is_specialization_of<_Class<_Args...>, _Class>
304 // pre: first != last
305 template<typename _CharT>
306 constexpr pair<unsigned short, const _CharT*>
307 __parse_integer(const _CharT* __first, const _CharT* __last)
309 if (__first == __last)
310 __builtin_unreachable();
312 if constexpr (is_same_v<_CharT, char>)
314 const auto __start = __first;
315 unsigned short __val = 0;
316 // N.B. std::from_chars is not constexpr in C++20.
317 if (__detail::__from_chars_alnum<true>(__first, __last, __val, 10)
318 && __first != __start) [[likely]]
319 return {__val, __first};
323 constexpr int __n = 32;
325 for (int __i = 0; __i < __n && (__first + __i) != __last; ++__i)
326 __buf[__i] = __first[__i];
327 auto [__v, __ptr] = __format::__parse_integer(__buf, __buf + __n);
328 if (__ptr) [[likely]]
329 return {__v, __first + (__ptr - __buf)};
334 template<typename _CharT>
335 constexpr pair<unsigned short, const _CharT*>
336 __parse_arg_id(const _CharT* __first, const _CharT* __last)
338 if (__first == __last)
339 __builtin_unreachable();
342 return {0, __first + 1}; // No leading zeros allowed, so '0...' == 0
344 if ('1' <= *__first && *__first <= '9')
346 const unsigned short __id = *__first - '0';
347 const auto __next = __first + 1;
348 // Optimize for most likely case of single digit arg-id.
349 if (__next == __last || !('0' <= *__next && *__next <= '9'))
350 return {__id, __next};
352 return __format::__parse_integer(__first, __last);
358 _Pres_none = 0, // Default type (not valid for integer presentation types).
359 // Presentation types for integral types (including bool and charT).
360 _Pres_d = 1, _Pres_b, _Pres_B, _Pres_o, _Pres_x, _Pres_X, _Pres_c,
361 // Presentation types for floating-point types.
362 _Pres_a = 1, _Pres_A, _Pres_e, _Pres_E, _Pres_f, _Pres_F, _Pres_g, _Pres_G,
363 _Pres_p = 0, _Pres_P, // For pointers.
364 _Pres_s = 0, // For strings and bool.
365 _Pres_esc = 0xf, // For strings and charT.
378 _Sign_minus, // XXX does this need to be distinct from _Sign_default?
383 _WP_none, // No width/prec specified.
384 _WP_value, // Fixed width/prec specified.
385 _WP_from_arg // Use a formatting argument for width/prec.
388 template<typename _Context>
390 __int_from_arg(const basic_format_arg<_Context>& __arg);
392 constexpr bool __is_digit(char __c)
393 { return std::__detail::__from_chars_alnum_to_val(__c) < 10; }
395 constexpr bool __is_xdigit(char __c)
396 { return std::__detail::__from_chars_alnum_to_val(__c) < 16; }
398 template<typename _CharT>
404 unsigned _M_localized : 1;
405 unsigned _M_zero_fill : 1;
406 _WidthPrec _M_width_kind : 2;
407 _WidthPrec _M_prec_kind : 2;
408 _Pres_type _M_type : 4;
409 unsigned _M_reserved : 1;
410 unsigned _M_reserved2 : 16;
411 unsigned short _M_width;
412 unsigned short _M_prec;
413 char32_t _M_fill = ' ';
415 using iterator = typename basic_string_view<_CharT>::iterator;
417 static constexpr _Align
418 _S_align(_CharT __c) noexcept
422 case '<': return _Align_left;
423 case '>': return _Align_right;
424 case '^': return _Align_centre;
425 default: return _Align_default;
429 // pre: __first != __last
431 _M_parse_fill_and_align(iterator __first, iterator __last) noexcept
435 using namespace __unicode;
436 if constexpr (__literal_encoding_is_unicode<_CharT>())
438 // Accept any UCS scalar value as fill character.
439 _Utf32_view<ranges::subrange<iterator>> __uv({__first, __last});
442 auto __beg = __uv.begin();
443 char32_t __c = *__beg++;
444 if (__is_scalar_value(__c))
445 if (auto __next = __beg.base(); __next != __last)
446 if (_Align __align = _S_align(*__next))
454 else if (__last - __first >= 2)
455 if (_Align __align = _S_align(__first[1]))
462 if (_Align __align = _S_align(__first[0]))
472 static constexpr _Sign
473 _S_sign(_CharT __c) noexcept
477 case '+': return _Sign_plus;
478 case '-': return _Sign_minus;
479 case ' ': return _Sign_space;
480 default: return _Sign_default;
484 // pre: __first != __last
486 _M_parse_sign(iterator __first, iterator) noexcept
488 if (_Sign __sign = _S_sign(*__first))
496 // pre: *__first is valid
498 _M_parse_alternate_form(iterator __first, iterator) noexcept
508 // pre: __first != __last
510 _M_parse_zero_fill(iterator __first, iterator /* __last */) noexcept
520 // pre: __first != __last
521 static constexpr iterator
522 _S_parse_width_or_precision(iterator __first, iterator __last,
523 unsigned short& __val, bool& __arg_id,
524 basic_format_parse_context<_CharT>& __pc)
526 if (__format::__is_digit(*__first))
528 auto [__v, __ptr] = __format::__parse_integer(__first, __last);
530 __throw_format_error("format error: invalid width or precision "
535 else if (*__first == '{')
539 if (__first == __last)
540 __format::__unmatched_left_brace_in_format_string();
542 __val = __pc.next_arg_id();
545 auto [__v, __ptr] = __format::__parse_arg_id(__first, __last);
546 if (__ptr == nullptr || __ptr == __last || *__ptr != '}')
547 __format::__invalid_arg_id_in_format_string();
549 __pc.check_arg_id(__v);
552 ++__first; // past the '}'
557 // pre: __first != __last
559 _M_parse_width(iterator __first, iterator __last,
560 basic_format_parse_context<_CharT>& __pc)
562 bool __arg_id = false;
564 __throw_format_error("format error: width must be non-zero in "
566 auto __next = _S_parse_width_or_precision(__first, __last, _M_width,
568 if (__next != __first)
569 _M_width_kind = __arg_id ? _WP_from_arg : _WP_value;
573 // pre: __first != __last
575 _M_parse_precision(iterator __first, iterator __last,
576 basic_format_parse_context<_CharT>& __pc)
578 if (__first[0] != '.')
581 iterator __next = ++__first;
582 bool __arg_id = false;
583 if (__next != __last)
584 __next = _S_parse_width_or_precision(__first, __last, _M_prec,
586 if (__next == __first)
587 __throw_format_error("format error: missing precision after '.' in "
589 _M_prec_kind = __arg_id ? _WP_from_arg : _WP_value;
593 // pre: __first != __last
595 _M_parse_locale(iterator __first, iterator /* __last */) noexcept
605 template<typename _Context>
607 _M_get_width(_Context& __ctx) const
610 if (_M_width_kind == _WP_value)
612 else if (_M_width_kind == _WP_from_arg)
613 __width = __format::__int_from_arg(__ctx.arg(_M_width));
617 template<typename _Context>
619 _M_get_precision(_Context& __ctx) const
622 if (_M_prec_kind == _WP_value)
624 else if (_M_prec_kind == _WP_from_arg)
625 __prec = __format::__int_from_arg(__ctx.arg(_M_prec));
630 template<typename _Int>
632 __put_sign(_Int __i, _Sign __sign, char* __dest) noexcept
636 else if (__sign == _Sign_plus)
638 else if (__sign == _Sign_space)
645 // Write STR to OUT (and do so efficiently if OUT is a _Sink_iter).
646 template<typename _Out, typename _CharT>
647 requires output_iterator<_Out, const _CharT&>
649 __write(_Out __out, basic_string_view<_CharT> __str)
651 if constexpr (is_same_v<_Out, _Sink_iter<_CharT>>)
657 for (_CharT __c : __str)
662 // Write STR to OUT with NFILL copies of FILL_CHAR specified by ALIGN.
663 // pre: __align != _Align_default
664 template<typename _Out, typename _CharT>
666 __write_padded(_Out __out, basic_string_view<_CharT> __str,
667 _Align __align, size_t __nfill, char32_t __fill_char)
669 const size_t __buflen = 0x20;
670 _CharT __padding_chars[__buflen];
671 __padding_chars[0] = _CharT();
672 basic_string_view<_CharT> __padding{__padding_chars, __buflen};
674 auto __pad = [&__padding] (size_t __n, _Out& __o) {
677 while (__n > __padding.size())
679 __o = __format::__write(std::move(__o), __padding);
680 __n -= __padding.size();
683 __o = __format::__write(std::move(__o), __padding.substr(0, __n));
686 size_t __l, __r, __max;
687 if (__align == _Align_centre)
690 __r = __l + (__nfill & 1);
693 else if (__align == _Align_right)
706 using namespace __unicode;
707 if constexpr (__literal_encoding_is_unicode<_CharT>())
708 if (!__is_single_code_unit<_CharT>(__fill_char)) [[unlikely]]
710 // Encode fill char as multiple code units of type _CharT.
711 const char32_t __arr[1]{ __fill_char };
712 _Utf_view<_CharT, const char32_t(&)[1]> __v(__arr);
713 basic_string<_CharT> __padstr(__v.begin(), __v.end());
714 __padding = __padstr;
716 __out = __format::__write(std::move(__out), __padding);
717 __out = __format::__write(std::move(__out), __str);
719 __out = __format::__write(std::move(__out), __padding);
723 if (__max < __buflen)
724 __padding.remove_suffix(__buflen - __max);
728 char_traits<_CharT>::assign(__padding_chars, __max, __fill_char);
730 __out = __format::__write(std::move(__out), __str);
736 // Write STR to OUT, with alignment and padding as determined by SPEC.
737 // pre: __spec._M_align != _Align_default || __align != _Align_default
738 template<typename _CharT, typename _Out>
740 __write_padded_as_spec(basic_string_view<type_identity_t<_CharT>> __str,
741 size_t __estimated_width,
742 basic_format_context<_Out, _CharT>& __fc,
743 const _Spec<_CharT>& __spec,
744 _Align __align = _Align_left)
746 size_t __width = __spec._M_get_width(__fc);
748 if (__width <= __estimated_width)
749 return __format::__write(__fc.out(), __str);
751 const size_t __nfill = __width - __estimated_width;
754 __align = __spec._M_align;
756 return __format::__write_padded(__fc.out(), __str, __align, __nfill,
760 // A lightweight optional<locale>.
761 struct _Optional_locale
763 [[__gnu__::__always_inline__]]
764 _Optional_locale() : _M_dummy(), _M_hasval(false) { }
766 _Optional_locale(const locale& __loc) noexcept
767 : _M_loc(__loc), _M_hasval(true)
770 _Optional_locale(const _Optional_locale& __l) noexcept
771 : _M_dummy(), _M_hasval(__l._M_hasval)
774 std::construct_at(&_M_loc, __l._M_loc);
778 operator=(const _Optional_locale& __l) noexcept
790 else if (__l._M_hasval)
792 std::construct_at(&_M_loc, __l._M_loc);
798 ~_Optional_locale() { if (_M_hasval) _M_loc.~locale(); }
801 operator=(locale&& __loc) noexcept
804 _M_loc = std::move(__loc);
807 std::construct_at(&_M_loc, std::move(__loc));
818 std::construct_at(&_M_loc);
824 bool has_value() const noexcept { return _M_hasval; }
827 char _M_dummy = '\0';
830 bool _M_hasval = false;
833#ifdef _GLIBCXX_USE_WCHAR_T
834 template<typename _CharT>
835 concept __char = same_as<_CharT, char> || same_as<_CharT, wchar_t>;
837 template<typename _CharT>
838 concept __char = same_as<_CharT, char>;
841 template<__char _CharT>
842 struct __formatter_str
844 constexpr typename basic_format_parse_context<_CharT>::iterator
845 parse(basic_format_parse_context<_CharT>& __pc)
847 auto __first = __pc.begin();
848 const auto __last = __pc.end();
849 _Spec<_CharT> __spec{};
851 auto __finalize = [this, &__spec] {
855 auto __finished = [&] {
856 if (__first == __last || *__first == '}')
867 __first = __spec._M_parse_fill_and_align(__first, __last);
871 __first = __spec._M_parse_width(__first, __last, __pc);
875 __first = __spec._M_parse_precision(__first, __last, __pc);
881#if __cpp_lib_format_ranges
882 else if (*__first == '?')
884 __spec._M_type = _Pres_esc;
892 __format::__failed_to_parse_format_spec();
895 template<typename _Out>
897 format(basic_string_view<_CharT> __s,
898 basic_format_context<_Out, _CharT>& __fc) const
900 if (_M_spec._M_type == _Pres_esc)
902 // TODO: C++23 escaped string presentation
905 if (_M_spec._M_width_kind == _WP_none
906 && _M_spec._M_prec_kind == _WP_none)
907 return __format::__write(__fc.out(), __s);
909 size_t __estimated_width;
910 if constexpr (__unicode::__literal_encoding_is_unicode<_CharT>())
912 if (_M_spec._M_prec_kind != _WP_none)
914 size_t __prec = _M_spec._M_get_precision(__fc);
915 __estimated_width = __unicode::__truncate(__s, __prec);
918 __estimated_width = __unicode::__field_width(__s);
922 __s = __s.substr(0, _M_spec._M_get_precision(__fc));
923 __estimated_width = __s.size();
926 return __format::__write_padded_as_spec(__s, __estimated_width,
930#if __cpp_lib_format_ranges
932 set_debug_format() noexcept
933 { _M_spec._M_type = _Pres_esc; }
937 _Spec<_CharT> _M_spec{};
940 template<__char _CharT>
941 struct __formatter_int
943 // If no presentation type is specified, meaning of "none" depends
944 // whether we are formatting an integer or a char or a bool.
945 static constexpr _Pres_type _AsInteger = _Pres_d;
946 static constexpr _Pres_type _AsBool = _Pres_s;
947 static constexpr _Pres_type _AsChar = _Pres_c;
949 constexpr typename basic_format_parse_context<_CharT>::iterator
950 _M_do_parse(basic_format_parse_context<_CharT>& __pc, _Pres_type __type)
952 _Spec<_CharT> __spec{};
953 __spec._M_type = __type;
955 const auto __last = __pc.end();
956 auto __first = __pc.begin();
958 auto __finalize = [this, &__spec] {
962 auto __finished = [&] {
963 if (__first == __last || *__first == '}')
974 __first = __spec._M_parse_fill_and_align(__first, __last);
978 __first = __spec._M_parse_sign(__first, __last);
982 __first = __spec._M_parse_alternate_form(__first, __last);
986 __first = __spec._M_parse_zero_fill(__first, __last);
990 __first = __spec._M_parse_width(__first, __last, __pc);
994 __first = __spec._M_parse_locale(__first, __last);
1001 __spec._M_type = _Pres_b;
1005 __spec._M_type = _Pres_B;
1009 // _GLIBCXX_RESOLVE_LIB_DEFECTS
1010 // 3586. format should not print bool with 'c'
1011 if (__type != _AsBool)
1013 __spec._M_type = _Pres_c;
1018 __spec._M_type = _Pres_d;
1022 __spec._M_type = _Pres_o;
1026 __spec._M_type = _Pres_x;
1030 __spec._M_type = _Pres_X;
1034 if (__type == _AsBool)
1036 __spec._M_type = _Pres_s; // same value (and meaning) as "none"
1040#if __cpp_lib_format_ranges
1042 if (__type == _AsChar)
1044 __spec._M_type = _Pres_esc;
1054 __format::__failed_to_parse_format_spec();
1057 template<typename _Tp>
1058 constexpr typename basic_format_parse_context<_CharT>::iterator
1059 _M_parse(basic_format_parse_context<_CharT>& __pc)
1061 if constexpr (is_same_v<_Tp, bool>)
1063 auto __end = _M_do_parse(__pc, _AsBool);
1064 if (_M_spec._M_type == _Pres_s)
1065 if (_M_spec._M_sign || _M_spec._M_alt || _M_spec._M_zero_fill)
1066 __throw_format_error("format error: format-spec contains "
1067 "invalid formatting options for "
1071 else if constexpr (__char<_Tp>)
1073 auto __end = _M_do_parse(__pc, _AsChar);
1074 if (_M_spec._M_type == _Pres_c || _M_spec._M_type == _Pres_esc)
1075 if (_M_spec._M_sign || _M_spec._M_alt || _M_spec._M_zero_fill
1076 /* XXX should be invalid? || _M_spec._M_localized */)
1077 __throw_format_error("format error: format-spec contains "
1078 "invalid formatting options for "
1083 return _M_do_parse(__pc, _AsInteger);
1086 template<typename _Int, typename _Out>
1087 typename basic_format_context<_Out, _CharT>::iterator
1088 format(_Int __i, basic_format_context<_Out, _CharT>& __fc) const
1090 if (_M_spec._M_type == _Pres_c)
1091 return _M_format_character(_S_to_character(__i), __fc);
1093 char __buf[sizeof(_Int) * __CHAR_BIT__ + 3];
1094 to_chars_result __res{};
1096 string_view __base_prefix;
1097 make_unsigned_t<_Int> __u;
1099 __u = -static_cast<make_unsigned_t<_Int>>(__i);
1103 char* __start = __buf + 3;
1104 char* const __end = __buf + sizeof(__buf);
1105 char* const __start_digits = __start;
1107 switch (_M_spec._M_type)
1111 __base_prefix = _M_spec._M_type == _Pres_b ? "0b" : "0B";
1112 __res = to_chars(__start, __end, __u, 2);
1116 return _M_format_character(_S_to_character(__i), __fc);
1119 // Should not reach here with _Pres_none for bool or charT, so:
1122 __res = to_chars(__start, __end, __u, 10);
1126 __base_prefix = "0";
1127 __res = to_chars(__start, __end, __u, 8);
1131 __base_prefix = _M_spec._M_type == _Pres_x ? "0x" : "0X";
1132 __res = to_chars(__start, __end, __u, 16);
1133 if (_M_spec._M_type == _Pres_X)
1134 for (auto __p = __start; __p != __res.ptr; ++__p)
1135#if __has_builtin(__builtin_toupper)
1136 *__p = __builtin_toupper(*__p);
1138 *__p = std::toupper(*__p);
1142 __builtin_unreachable();
1145 if (_M_spec._M_alt && __base_prefix.size())
1147 __start -= __base_prefix.size();
1148 __builtin_memcpy(__start, __base_prefix.data(),
1149 __base_prefix.size());
1151 __start = __format::__put_sign(__i, _M_spec._M_sign, __start - 1);
1153 return _M_format_int(string_view(__start, __res.ptr - __start),
1154 __start_digits - __start, __fc);
1157 template<typename _Out>
1158 typename basic_format_context<_Out, _CharT>::iterator
1159 format(bool __i, basic_format_context<_Out, _CharT>& __fc) const
1161 if (_M_spec._M_type == _Pres_c)
1162 return _M_format_character(static_cast<unsigned char>(__i), __fc);
1163 if (_M_spec._M_type != _Pres_s)
1164 return format(static_cast<unsigned char>(__i), __fc);
1166 basic_string<_CharT> __s;
1168 if (_M_spec._M_localized) [[unlikely]]
1170 auto& __np = std::use_facet<numpunct<_CharT>>(__fc.locale());
1171 __s = __i ? __np.truename() : __np.falsename();
1172 __est_width = __s.size(); // TODO Unicode-aware estimate
1176 if constexpr (is_same_v<char, _CharT>)
1177 __s = __i ? "true" : "false";
1179 __s = __i ? L"true" : L"false";
1180 __est_width = __s.size();
1183 return __format::__write_padded_as_spec(__s, __est_width, __fc,
1187 template<typename _Out>
1188 typename basic_format_context<_Out, _CharT>::iterator
1189 _M_format_character(_CharT __c,
1190 basic_format_context<_Out, _CharT>& __fc) const
1192 return __format::__write_padded_as_spec({&__c, 1u}, 1, __fc, _M_spec);
1195 template<typename _Int>
1197 _S_to_character(_Int __i)
1199 using _Traits = __gnu_cxx::__int_traits<_CharT>;
1200 if constexpr (is_signed_v<_Int> == is_signed_v<_CharT>)
1202 if (_Traits::__min <= __i && __i <= _Traits::__max)
1203 return static_cast<_CharT>(__i);
1205 else if constexpr (is_signed_v<_Int>)
1207 if (__i >= 0 && make_unsigned_t<_Int>(__i) <= _Traits::__max)
1208 return static_cast<_CharT>(__i);
1210 else if (__i <= make_unsigned_t<_CharT>(_Traits::__max))
1211 return static_cast<_CharT>(__i);
1212 __throw_format_error("format error: integer not representable as "
1216 template<typename _Out>
1217 typename basic_format_context<_Out, _CharT>::iterator
1218 _M_format_int(string_view __narrow_str, size_t __prefix_len,
1219 basic_format_context<_Out, _CharT>& __fc) const
1221 size_t __width = _M_spec._M_get_width(__fc);
1223 basic_string_view<_CharT> __str;
1224 if constexpr (is_same_v<char, _CharT>)
1225 __str = __narrow_str;
1226#ifdef _GLIBCXX_USE_WCHAR_T
1229 size_t __n = __narrow_str.size();
1230 auto __p = (_CharT*)__builtin_alloca(__n * sizeof(_CharT));
1231 std::__to_wstring_numeric(__narrow_str.data(), __n, __p);
1236 if (_M_spec._M_localized)
1238 const auto& __l = __fc.locale();
1239 if (__l.name() != "C")
1241 auto& __np = use_facet<numpunct<_CharT>>(__l);
1242 string __grp = __np.grouping();
1245 size_t __n = __str.size() - __prefix_len;
1246 auto __p = (_CharT*)__builtin_alloca(2 * __n
1249 auto __s = __str.data();
1250 char_traits<_CharT>::copy(__p, __s, __prefix_len);
1251 __s += __prefix_len;
1252 auto __end = std::__add_grouping(__p + __prefix_len,
1253 __np.thousands_sep(),
1257 __str = {__p, size_t(__end - __p)};
1262 if (__width <= __str.size())
1263 return __format::__write(__fc.out(), __str);
1265 char32_t __fill_char = _M_spec._M_fill;
1266 _Align __align = _M_spec._M_align;
1268 size_t __nfill = __width - __str.size();
1269 auto __out = __fc.out();
1270 if (__align == _Align_default)
1272 __align = _Align_right;
1273 if (_M_spec._M_zero_fill)
1275 __fill_char = _CharT('0');
1276 // Write sign and base prefix before zero filling.
1277 if (__prefix_len != 0)
1279 __out = __format::__write(std::move(__out),
1280 __str.substr(0, __prefix_len));
1281 __str.remove_prefix(__prefix_len);
1285 __fill_char = _CharT(' ');
1287 return __format::__write_padded(std::move(__out), __str,
1288 __align, __nfill, __fill_char);
1291#if defined __SIZEOF_INT128__ && defined __STRICT_ANSI__
1292 template<typename _Tp>
1293 using make_unsigned_t
1294 = typename __conditional_t<(sizeof(_Tp) <= sizeof(long long)),
1295 std::make_unsigned<_Tp>,
1296 type_identity<unsigned __int128>>::type;
1298 // std::to_chars is not overloaded for int128 in strict mode.
1299 template<typename _Int>
1300 static to_chars_result
1301 to_chars(char* __first, char* __last, _Int __value, int __base)
1302 { return std::__to_chars_i<_Int>(__first, __last, __value, __base); }
1305 _Spec<_CharT> _M_spec{};
1308 // Decide how 128-bit floating-point types should be formatted (or not).
1309 // When supported, the typedef __format::__float128_t is the type that
1310 // format arguments should be converted to for storage in basic_format_arg.
1311 // Define the macro _GLIBCXX_FORMAT_F128 to say they're supported.
1312 // _GLIBCXX_FORMAT_F128=1 means __float128, _Float128 etc. will be formatted
1313 // by converting them to long double (or __ieee128 for powerpc64le).
1314 // _GLIBCXX_FORMAT_F128=2 means basic_format_arg needs to enable explicit
1315 // support for _Float128, rather than formatting it as another type.
1316#undef _GLIBCXX_FORMAT_F128
1318#ifdef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
1320 // Format 128-bit floating-point types using __ieee128.
1321 using __float128_t = __ieee128;
1322# define _GLIBCXX_FORMAT_F128 1
1324#ifdef __LONG_DOUBLE_IEEE128__
1325 // These overloads exist in the library, but are not declared.
1326 // Make them available as std::__format::to_chars.
1328 to_chars(char*, char*, __ibm128) noexcept
1329 __asm("_ZSt8to_charsPcS_e");
1332 to_chars(char*, char*, __ibm128, chars_format) noexcept
1333 __asm("_ZSt8to_charsPcS_eSt12chars_format");
1336 to_chars(char*, char*, __ibm128, chars_format, int) noexcept
1337 __asm("_ZSt8to_charsPcS_eSt12chars_formati");
1338#elif __cplusplus == 202002L
1340 to_chars(char*, char*, __ieee128) noexcept
1341 __asm("_ZSt8to_charsPcS_u9__ieee128");
1344 to_chars(char*, char*, __ieee128, chars_format) noexcept
1345 __asm("_ZSt8to_charsPcS_u9__ieee128St12chars_format");
1348 to_chars(char*, char*, __ieee128, chars_format, int) noexcept
1349 __asm("_ZSt8to_charsPcS_u9__ieee128St12chars_formati");
1352#elif defined _GLIBCXX_LDOUBLE_IS_IEEE_BINARY128
1354 // Format 128-bit floating-point types using long double.
1355 using __float128_t = long double;
1356# define _GLIBCXX_FORMAT_F128 1
1358#elif __FLT128_DIG__ && defined(_GLIBCXX_HAVE_FLOAT128_MATH)
1360 // Format 128-bit floating-point types using _Float128.
1361 using __float128_t = _Float128;
1362# define _GLIBCXX_FORMAT_F128 2
1364# if __cplusplus == 202002L
1365 // These overloads exist in the library, but are not declared for C++20.
1366 // Make them available as std::__format::to_chars.
1368 to_chars(char*, char*, _Float128) noexcept
1369# if _GLIBCXX_INLINE_VERSION
1370 __asm("_ZNSt3__88to_charsEPcS0_DF128_");
1372 __asm("_ZSt8to_charsPcS_DF128_");
1376 to_chars(char*, char*, _Float128, chars_format) noexcept
1377# if _GLIBCXX_INLINE_VERSION
1378 __asm("_ZNSt3__88to_charsEPcS0_DF128_NS_12chars_formatE");
1380 __asm("_ZSt8to_charsPcS_DF128_St12chars_format");
1384 to_chars(char*, char*, _Float128, chars_format, int) noexcept
1385# if _GLIBCXX_INLINE_VERSION
1386 __asm("_ZNSt3__88to_charsEPcS0_DF128_NS_12chars_formatEi");
1388 __asm("_ZSt8to_charsPcS_DF128_St12chars_formati");
1393 using std::to_chars;
1395 // We can format a floating-point type iff it is usable with to_chars.
1396 template<typename _Tp>
1397 concept __formattable_float
1398 = is_same_v<remove_cv_t<_Tp>, _Tp> && requires (_Tp __t, char* __p)
1399 { __format::to_chars(__p, __p, __t, chars_format::scientific, 6); };
1401 template<__char _CharT>
1402 struct __formatter_fp
1404 constexpr typename basic_format_parse_context<_CharT>::iterator
1405 parse(basic_format_parse_context<_CharT>& __pc)
1407 _Spec<_CharT> __spec{};
1408 const auto __last = __pc.end();
1409 auto __first = __pc.begin();
1411 auto __finalize = [this, &__spec] {
1415 auto __finished = [&] {
1416 if (__first == __last || *__first == '}')
1427 __first = __spec._M_parse_fill_and_align(__first, __last);
1431 __first = __spec._M_parse_sign(__first, __last);
1435 __first = __spec._M_parse_alternate_form(__first, __last);
1439 __first = __spec._M_parse_zero_fill(__first, __last);
1443 if (__first[0] != '.')
1445 __first = __spec._M_parse_width(__first, __last, __pc);
1450 __first = __spec._M_parse_precision(__first, __last, __pc);
1454 __first = __spec._M_parse_locale(__first, __last);
1461 __spec._M_type = _Pres_a;
1465 __spec._M_type = _Pres_A;
1469 __spec._M_type = _Pres_e;
1473 __spec._M_type = _Pres_E;
1477 __spec._M_type = _Pres_f;
1481 __spec._M_type = _Pres_F;
1485 __spec._M_type = _Pres_g;
1489 __spec._M_type = _Pres_G;
1497 __format::__failed_to_parse_format_spec();
1500 template<typename _Fp, typename _Out>
1501 typename basic_format_context<_Out, _CharT>::iterator
1502 format(_Fp __v, basic_format_context<_Out, _CharT>& __fc) const
1504 std::string __dynbuf;
1506 to_chars_result __res{};
1509 bool __use_prec = _M_spec._M_prec_kind != _WP_none;
1511 __prec = _M_spec._M_get_precision(__fc);
1513 char* __start = __buf + 1; // reserve space for sign
1514 char* __end = __buf + sizeof(__buf);
1516 chars_format __fmt{};
1517 bool __upper = false;
1518 bool __trailing_zeros = false;
1521 switch (_M_spec._M_type)
1528 if (_M_spec._M_type != _Pres_A)
1530 __fmt = chars_format::hex;
1538 __fmt = chars_format::scientific;
1545 __fmt = chars_format::fixed;
1552 __trailing_zeros = true;
1554 __fmt = chars_format::general;
1558 __fmt = chars_format::general;
1561 __builtin_unreachable();
1564 // Write value into buffer using std::to_chars.
1565 auto __to_chars = [&](char* __b, char* __e) {
1567 return __format::to_chars(__b, __e, __v, __fmt, __prec);
1568 else if (__fmt != chars_format{})
1569 return __format::to_chars(__b, __e, __v, __fmt);
1571 return __format::to_chars(__b, __e, __v);
1574 // First try using stack buffer.
1575 __res = __to_chars(__start, __end);
1577 if (__builtin_expect(__res.ec == errc::value_too_large, 0))
1579 // If the buffer is too small it's probably because of a large
1580 // precision, or a very large value in fixed format.
1581 size_t __guess = 8 + __prec;
1582 if (__fmt == chars_format::fixed) // +ddd.prec
1584 if constexpr (is_same_v<_Fp, float> || is_same_v<_Fp, double>
1585 || is_same_v<_Fp, long double>)
1587 // The number of digits to the left of the decimal point
1588 // is floor(log10(max(abs(__v),1)))+1
1590 if constexpr (is_same_v<_Fp, float>)
1591 __builtin_frexpf(__v, &__exp);
1592 else if constexpr (is_same_v<_Fp, double>)
1593 __builtin_frexp(__v, &__exp);
1594 else if constexpr (is_same_v<_Fp, long double>)
1595 __builtin_frexpl(__v, &__exp);
1597 __guess += 1U + __exp * 4004U / 13301U; // log10(2) approx.
1600 __guess += numeric_limits<_Fp>::max_exponent10;
1602 if (__guess <= sizeof(__buf)) [[unlikely]]
1603 __guess = sizeof(__buf) * 2;
1604 __dynbuf.reserve(__guess);
1608 auto __overwrite = [&__to_chars, &__res] (char* __p, size_t __n)
1610 __res = __to_chars(__p + 1, __p + __n - 1);
1611 return __res.ec == errc{} ? __res.ptr - __p : 0;
1614 __dynbuf.__resize_and_overwrite(__dynbuf.capacity() * 2,
1616 __start = __dynbuf.data() + 1; // reserve space for sign
1617 __end = __dynbuf.data() + __dynbuf.size();
1619 while (__builtin_expect(__res.ec == errc::value_too_large, 0));
1622 // Use uppercase for 'A', 'E', and 'G' formats.
1625 for (char* __p = __start; __p != __res.ptr; ++__p)
1626 *__p = std::toupper(*__p);
1629 bool __have_sign = true;
1630 // Add sign for non-negative values.
1631 if (!__builtin_signbit(__v))
1633 if (_M_spec._M_sign == _Sign_plus)
1635 else if (_M_spec._M_sign == _Sign_space)
1638 __have_sign = false;
1641 string_view __narrow_str(__start, __res.ptr - __start);
1643 // Use alternate form. Ensure decimal point is always present,
1644 // and add trailing zeros (up to precision) for g and G forms.
1645 if (_M_spec._M_alt && __builtin_isfinite(__v))
1647 string_view __s = __narrow_str;
1648 size_t __sigfigs; // Number of significant figures.
1649 size_t __z = 0; // Number of trailing zeros to add.
1650 size_t __p; // Position of the exponent character (if any).
1651 size_t __d = __s.find('.'); // Position of decimal point.
1652 if (__d != __s.npos) // Found decimal point.
1654 __p = __s.find(__expc, __d + 1);
1655 if (__p == __s.npos)
1658 // If presentation type is g or G we might need to add zeros.
1659 if (__trailing_zeros)
1661 // Find number of digits after first significant figure.
1662 if (__s[__have_sign] != '0')
1663 // A string like "D.D" or "-D.DDD"
1664 __sigfigs = __p - __have_sign - 1;
1666 // A string like "0.D" or "-0.0DD".
1667 // Safe to assume there is a non-zero digit, because
1668 // otherwise there would be no decimal point.
1669 __sigfigs = __p - __s.find_first_not_of('0', __d + 1);
1672 else // No decimal point, we need to insert one.
1674 __p = __s.find(__expc); // Find the exponent, if present.
1675 if (__p == __s.npos)
1677 __d = __p; // Position where '.' should be inserted.
1678 __sigfigs = __d - __have_sign;
1681 if (__trailing_zeros && __prec != 0)
1683 // For g and G presentation types std::to_chars produces
1684 // no more than prec significant figures. Insert this many
1685 // zeros so the result has exactly prec significant figures.
1686 __z = __prec - __sigfigs;
1689 if (size_t __extras = int(__d == __p) + __z) // How many to add.
1691 if (__dynbuf.empty() && __extras <= size_t(__end - __res.ptr))
1693 // The stack buffer is large enough for the result.
1694 // Move exponent to make space for extra chars.
1695 __builtin_memmove(__start + __p + __extras,
1699 __start[__p++] = '.';
1700 __builtin_memset(__start + __p, '0', __z);
1701 __narrow_str = {__s.data(), __s.size() + __extras};
1703 else // Need to switch to the dynamic buffer.
1705 __dynbuf.reserve(__s.size() + __extras);
1706 if (__dynbuf.empty())
1708 __dynbuf = __s.substr(0, __p);
1712 __dynbuf.append(__z, '0');
1713 __dynbuf.append(__s.substr(__p));
1717 __dynbuf.insert(__p, __extras, '0');
1719 __dynbuf[__p] = '.';
1721 __narrow_str = __dynbuf;
1726 basic_string<_CharT> __wstr;
1727 basic_string_view<_CharT> __str;
1728 if constexpr (is_same_v<_CharT, char>)
1729 __str = __narrow_str;
1730#ifdef _GLIBCXX_USE_WCHAR_T
1733 __wstr = std::__to_wstring_numeric(__narrow_str);
1738 if (_M_spec._M_localized && __builtin_isfinite(__v))
1740 __wstr = _M_localize(__str, __expc, __fc.locale());
1741 if (!__wstr.empty())
1745 size_t __width = _M_spec._M_get_width(__fc);
1747 if (__width <= __str.size())
1748 return __format::__write(__fc.out(), __str);
1750 char32_t __fill_char = _M_spec._M_fill;
1751 _Align __align = _M_spec._M_align;
1753 size_t __nfill = __width - __str.size();
1754 auto __out = __fc.out();
1755 if (__align == _Align_default)
1757 __align = _Align_right;
1758 if (_M_spec._M_zero_fill && __builtin_isfinite(__v))
1760 __fill_char = _CharT('0');
1761 // Write sign before zero filling.
1762 if (!__format::__is_xdigit(__narrow_str[0]))
1764 *__out++ = __str[0];
1765 __str.remove_prefix(1);
1769 __fill_char = _CharT(' ');
1771 return __format::__write_padded(std::move(__out), __str,
1772 __align, __nfill, __fill_char);
1775 // Locale-specific format.
1776 basic_string<_CharT>
1777 _M_localize(basic_string_view<_CharT> __str, char __expc,
1778 const locale& __loc) const
1780 basic_string<_CharT> __lstr;
1782 if (__loc == locale::classic())
1783 return __lstr; // Nothing to do.
1785 const auto& __np = use_facet<numpunct<_CharT>>(__loc);
1786 const _CharT __point = __np.decimal_point();
1787 const string __grp = __np.grouping();
1789 _CharT __dot, __exp;
1790 if constexpr (is_same_v<_CharT, char>)
1813 __builtin_unreachable();
1817 if (__grp.empty() && __point == __dot)
1818 return __lstr; // Locale uses '.' and no grouping.
1820 size_t __d = __str.find(__dot);
1821 size_t __e = min(__d, __str.find(__exp));
1822 if (__e == __str.npos)
1824 const size_t __r = __str.size() - __e;
1825 auto __overwrite = [&](_CharT* __p, size_t) {
1826 auto __end = std::__add_grouping(__p, __np.thousands_sep(),
1827 __grp.data(), __grp.size(),
1828 __str.data(), __str.data() + __e);
1831 if (__d != __str.npos)
1838 __end += __str.copy(__end, __str.npos, __e);
1840 return (__end - __p);
1842 __lstr.__resize_and_overwrite(__e * 2 + __r, __overwrite);
1846 _Spec<_CharT> _M_spec{};
1849} // namespace __format
1852 /// Format a character.
1853 template<__format::__char _CharT>
1854 struct formatter<_CharT, _CharT>
1856 formatter() = default;
1858 constexpr typename basic_format_parse_context<_CharT>::iterator
1859 parse(basic_format_parse_context<_CharT>& __pc)
1861 return _M_f.template _M_parse<_CharT>(__pc);
1864 template<typename _Out>
1865 typename basic_format_context<_Out, _CharT>::iterator
1866 format(_CharT __u, basic_format_context<_Out, _CharT>& __fc) const
1868 if (_M_f._M_spec._M_type == __format::_Pres_none
1869 || _M_f._M_spec._M_type == __format::_Pres_c)
1870 return _M_f._M_format_character(__u, __fc);
1871 else if (_M_f._M_spec._M_type == __format::_Pres_esc)
1877 return _M_f.format(static_cast<make_unsigned_t<_CharT>>(__u), __fc);
1880#if __cpp_lib_format_ranges
1882 set_debug_format() noexcept
1883 { _M_f._M_spec._M_type = __format::_Pres_esc; }
1887 __format::__formatter_int<_CharT> _M_f;
1890#ifdef _GLIBCXX_USE_WCHAR_T
1891 /// Format a char value for wide character output.
1893 struct formatter<char, wchar_t>
1895 formatter() = default;
1897 constexpr typename basic_format_parse_context<wchar_t>::iterator
1898 parse(basic_format_parse_context<wchar_t>& __pc)
1900 return _M_f._M_parse<char>(__pc);
1903 template<typename _Out>
1904 typename basic_format_context<_Out, wchar_t>::iterator
1905 format(char __u, basic_format_context<_Out, wchar_t>& __fc) const
1907 if (_M_f._M_spec._M_type == __format::_Pres_none
1908 || _M_f._M_spec._M_type == __format::_Pres_c)
1909 return _M_f._M_format_character(__u, __fc);
1910 else if (_M_f._M_spec._M_type == __format::_Pres_esc)
1916 return _M_f.format(static_cast<unsigned char>(__u), __fc);
1919#if __cpp_lib_format_ranges
1921 set_debug_format() noexcept
1922 { _M_f._M_spec._M_type = __format::_Pres_esc; }
1926 __format::__formatter_int<wchar_t> _M_f;
1928#endif // USE_WCHAR_T
1930 /** Format a string.
1933 template<__format::__char _CharT>
1934 struct formatter<_CharT*, _CharT>
1936 formatter() = default;
1938 [[__gnu__::__always_inline__]]
1939 constexpr typename basic_format_parse_context<_CharT>::iterator
1940 parse(basic_format_parse_context<_CharT>& __pc)
1941 { return _M_f.parse(__pc); }
1943 template<typename _Out>
1944 [[__gnu__::__nonnull__]]
1945 typename basic_format_context<_Out, _CharT>::iterator
1946 format(_CharT* __u, basic_format_context<_Out, _CharT>& __fc) const
1947 { return _M_f.format(__u, __fc); }
1949#if __cpp_lib_format_ranges
1950 constexpr void set_debug_format() noexcept { _M_f.set_debug_format(); }
1954 __format::__formatter_str<_CharT> _M_f;
1957 template<__format::__char _CharT>
1958 struct formatter<const _CharT*, _CharT>
1960 formatter() = default;
1962 [[__gnu__::__always_inline__]]
1963 constexpr typename basic_format_parse_context<_CharT>::iterator
1964 parse(basic_format_parse_context<_CharT>& __pc)
1965 { return _M_f.parse(__pc); }
1967 template<typename _Out>
1968 [[__gnu__::__nonnull__]]
1969 typename basic_format_context<_Out, _CharT>::iterator
1970 format(const _CharT* __u,
1971 basic_format_context<_Out, _CharT>& __fc) const
1972 { return _M_f.format(__u, __fc); }
1974#if __cpp_lib_format_ranges
1975 constexpr void set_debug_format() noexcept { _M_f.set_debug_format(); }
1979 __format::__formatter_str<_CharT> _M_f;
1982 template<__format::__char _CharT, size_t _Nm>
1983 struct formatter<_CharT[_Nm], _CharT>
1985 formatter() = default;
1987 [[__gnu__::__always_inline__]]
1988 constexpr typename basic_format_parse_context<_CharT>::iterator
1989 parse(basic_format_parse_context<_CharT>& __pc)
1990 { return _M_f.parse(__pc); }
1992 template<typename _Out>
1993 typename basic_format_context<_Out, _CharT>::iterator
1994 format(const _CharT (&__u)[_Nm],
1995 basic_format_context<_Out, _CharT>& __fc) const
1996 { return _M_f.format({__u, _Nm}, __fc); }
1998#if __cpp_lib_format_ranges
1999 constexpr void set_debug_format() noexcept { _M_f.set_debug_format(); }
2003 __format::__formatter_str<_CharT> _M_f;
2006 template<typename _Traits, typename _Alloc>
2007 struct formatter<basic_string<char, _Traits, _Alloc>, char>
2009 formatter() = default;
2011 [[__gnu__::__always_inline__]]
2012 constexpr typename basic_format_parse_context<char>::iterator
2013 parse(basic_format_parse_context<char>& __pc)
2014 { return _M_f.parse(__pc); }
2016 template<typename _Out>
2017 typename basic_format_context<_Out, char>::iterator
2018 format(const basic_string<char, _Traits, _Alloc>& __u,
2019 basic_format_context<_Out, char>& __fc) const
2020 { return _M_f.format(__u, __fc); }
2022#if __cpp_lib_format_ranges
2023 constexpr void set_debug_format() noexcept { _M_f.set_debug_format(); }
2027 __format::__formatter_str<char> _M_f;
2030#ifdef _GLIBCXX_USE_WCHAR_T
2031 template<typename _Traits, typename _Alloc>
2032 struct formatter<basic_string<wchar_t, _Traits, _Alloc>, wchar_t>
2034 formatter() = default;
2036 [[__gnu__::__always_inline__]]
2037 constexpr typename basic_format_parse_context<wchar_t>::iterator
2038 parse(basic_format_parse_context<wchar_t>& __pc)
2039 { return _M_f.parse(__pc); }
2041 template<typename _Out>
2042 typename basic_format_context<_Out, wchar_t>::iterator
2043 format(const basic_string<wchar_t, _Traits, _Alloc>& __u,
2044 basic_format_context<_Out, wchar_t>& __fc) const
2045 { return _M_f.format(__u, __fc); }
2047#if __cpp_lib_format_ranges
2048 constexpr void set_debug_format() noexcept { _M_f.set_debug_format(); }
2052 __format::__formatter_str<wchar_t> _M_f;
2054#endif // USE_WCHAR_T
2056 template<typename _Traits>
2057 struct formatter<basic_string_view<char, _Traits>, char>
2059 formatter() = default;
2061 [[__gnu__::__always_inline__]]
2062 constexpr typename basic_format_parse_context<char>::iterator
2063 parse(basic_format_parse_context<char>& __pc)
2064 { return _M_f.parse(__pc); }
2066 template<typename _Out>
2067 typename basic_format_context<_Out, char>::iterator
2068 format(basic_string_view<char, _Traits> __u,
2069 basic_format_context<_Out, char>& __fc) const
2070 { return _M_f.format(__u, __fc); }
2072#if __cpp_lib_format_ranges
2073 constexpr void set_debug_format() noexcept { _M_f.set_debug_format(); }
2077 __format::__formatter_str<char> _M_f;
2080#ifdef _GLIBCXX_USE_WCHAR_T
2081 template<typename _Traits>
2082 struct formatter<basic_string_view<wchar_t, _Traits>, wchar_t>
2084 formatter() = default;
2086 [[__gnu__::__always_inline__]]
2087 constexpr typename basic_format_parse_context<wchar_t>::iterator
2088 parse(basic_format_parse_context<wchar_t>& __pc)
2089 { return _M_f.parse(__pc); }
2091 template<typename _Out>
2092 typename basic_format_context<_Out, wchar_t>::iterator
2093 format(basic_string_view<wchar_t, _Traits> __u,
2094 basic_format_context<_Out, wchar_t>& __fc) const
2095 { return _M_f.format(__u, __fc); }
2097#if __cpp_lib_format_ranges
2098 constexpr void set_debug_format() noexcept { _M_f.set_debug_format(); }
2102 __format::__formatter_str<wchar_t> _M_f;
2104#endif // USE_WCHAR_T
2107/// @cond undocumented
2110 // each cv-unqualified arithmetic type ArithmeticT other than
2111 // char, wchar_t, char8_t, char16_t, or char32_t
2112 template<typename _Tp>
2113 constexpr bool __is_formattable_integer = __is_integer<_Tp>::__value;
2115#if defined __SIZEOF_INT128__
2116 template<> inline constexpr bool __is_formattable_integer<__int128> = true;
2117 template<> inline constexpr bool __is_formattable_integer<unsigned __int128>
2121 template<> inline constexpr bool __is_formattable_integer<char> = false;
2122 template<> inline constexpr bool __is_formattable_integer<wchar_t> = false;
2123#ifdef _GLIBCXX_USE_CHAR8_T
2124 template<> inline constexpr bool __is_formattable_integer<char8_t> = false;
2126 template<> inline constexpr bool __is_formattable_integer<char16_t> = false;
2127 template<> inline constexpr bool __is_formattable_integer<char32_t> = false;
2131 /// Format an integer.
2132 template<typename _Tp, __format::__char _CharT>
2133 requires __format::__is_formattable_integer<_Tp>
2134 struct formatter<_Tp, _CharT>
2136 formatter() = default;
2138 [[__gnu__::__always_inline__]]
2139 constexpr typename basic_format_parse_context<_CharT>::iterator
2140 parse(basic_format_parse_context<_CharT>& __pc)
2142 return _M_f.template _M_parse<_Tp>(__pc);
2145 template<typename _Out>
2146 typename basic_format_context<_Out, _CharT>::iterator
2147 format(_Tp __u, basic_format_context<_Out, _CharT>& __fc) const
2148 { return _M_f.format(__u, __fc); }
2151 __format::__formatter_int<_CharT> _M_f;
2154#if defined __glibcxx_to_chars
2155 /// Format a floating-point value.
2156 template<__format::__formattable_float _Tp, __format::__char _CharT>
2157 struct formatter<_Tp, _CharT>
2159 formatter() = default;
2161 [[__gnu__::__always_inline__]]
2162 constexpr typename basic_format_parse_context<_CharT>::iterator
2163 parse(basic_format_parse_context<_CharT>& __pc)
2164 { return _M_f.parse(__pc); }
2166 template<typename _Out>
2167 typename basic_format_context<_Out, _CharT>::iterator
2168 format(_Tp __u, basic_format_context<_Out, _CharT>& __fc) const
2169 { return _M_f.format(__u, __fc); }
2172 __format::__formatter_fp<_CharT> _M_f;
2175#if __LDBL_MANT_DIG__ == __DBL_MANT_DIG__
2176 // Reuse __formatter_fp<C>::format<double, Out> for long double.
2177 template<__format::__char _CharT>
2178 struct formatter<long double, _CharT>
2180 formatter() = default;
2182 [[__gnu__::__always_inline__]]
2183 constexpr typename basic_format_parse_context<_CharT>::iterator
2184 parse(basic_format_parse_context<_CharT>& __pc)
2185 { return _M_f.parse(__pc); }
2187 template<typename _Out>
2188 typename basic_format_context<_Out, _CharT>::iterator
2189 format(long double __u, basic_format_context<_Out, _CharT>& __fc) const
2190 { return _M_f.format((double)__u, __fc); }
2193 __format::__formatter_fp<_CharT> _M_f;
2197#ifdef __STDCPP_FLOAT16_T__
2198 // Reuse __formatter_fp<C>::format<float, Out> for _Float16.
2199 template<__format::__char _CharT>
2200 struct formatter<_Float16, _CharT>
2202 formatter() = default;
2204 [[__gnu__::__always_inline__]]
2205 constexpr typename basic_format_parse_context<_CharT>::iterator
2206 parse(basic_format_parse_context<_CharT>& __pc)
2207 { return _M_f.parse(__pc); }
2209 template<typename _Out>
2210 typename basic_format_context<_Out, _CharT>::iterator
2211 format(_Float16 __u, basic_format_context<_Out, _CharT>& __fc) const
2212 { return _M_f.format((float)__u, __fc); }
2215 __format::__formatter_fp<_CharT> _M_f;
2219#if defined(__FLT32_DIG__)
2220 // Reuse __formatter_fp<C>::format<float, Out> for _Float32.
2221 template<__format::__char _CharT>
2222 struct formatter<_Float32, _CharT>
2224 formatter() = default;
2226 [[__gnu__::__always_inline__]]
2227 constexpr typename basic_format_parse_context<_CharT>::iterator
2228 parse(basic_format_parse_context<_CharT>& __pc)
2229 { return _M_f.parse(__pc); }
2231 template<typename _Out>
2232 typename basic_format_context<_Out, _CharT>::iterator
2233 format(_Float32 __u, basic_format_context<_Out, _CharT>& __fc) const
2234 { return _M_f.format((float)__u, __fc); }
2237 __format::__formatter_fp<_CharT> _M_f;
2241#if defined(__FLT64_DIG__)
2242 // Reuse __formatter_fp<C>::format<double, Out> for _Float64.
2243 template<__format::__char _CharT>
2244 struct formatter<_Float64, _CharT>
2246 formatter() = default;
2248 [[__gnu__::__always_inline__]]
2249 constexpr typename basic_format_parse_context<_CharT>::iterator
2250 parse(basic_format_parse_context<_CharT>& __pc)
2251 { return _M_f.parse(__pc); }
2253 template<typename _Out>
2254 typename basic_format_context<_Out, _CharT>::iterator
2255 format(_Float64 __u, basic_format_context<_Out, _CharT>& __fc) const
2256 { return _M_f.format((double)__u, __fc); }
2259 __format::__formatter_fp<_CharT> _M_f;
2263#if defined(__FLT128_DIG__) && _GLIBCXX_FORMAT_F128 == 1
2264 // Reuse __formatter_fp<C>::format<__float128_t, Out> for _Float128.
2265 template<__format::__char _CharT>
2266 struct formatter<_Float128, _CharT>
2268 formatter() = default;
2270 [[__gnu__::__always_inline__]]
2271 constexpr typename basic_format_parse_context<_CharT>::iterator
2272 parse(basic_format_parse_context<_CharT>& __pc)
2273 { return _M_f.parse(__pc); }
2275 template<typename _Out>
2276 typename basic_format_context<_Out, _CharT>::iterator
2277 format(_Float128 __u, basic_format_context<_Out, _CharT>& __fc) const
2278 { return _M_f.format((__format::__float128_t)__u, __fc); }
2281 __format::__formatter_fp<_CharT> _M_f;
2285#ifdef __STDCPP_BFLOAT16_T__
2286 // Reuse __formatter_fp<C>::format<float, Out> for bfloat16_t.
2287 template<__format::__char _CharT>
2288 struct formatter<__gnu_cxx::__bfloat16_t, _CharT>
2290 formatter() = default;
2292 [[__gnu__::__always_inline__]]
2293 constexpr typename basic_format_parse_context<_CharT>::iterator
2294 parse(basic_format_parse_context<_CharT>& __pc)
2295 { return _M_f.parse(__pc); }
2297 template<typename _Out>
2298 typename basic_format_context<_Out, _CharT>::iterator
2299 format(__gnu_cxx::__bfloat16_t __u,
2300 basic_format_context<_Out, _CharT>& __fc) const
2301 { return _M_f.format((float)__u, __fc); }
2304 __format::__formatter_fp<_CharT> _M_f;
2307#endif // __cpp_lib_to_chars
2309 /** Format a pointer.
2312 template<__format::__char _CharT>
2313 struct formatter<const void*, _CharT>
2315 formatter() = default;
2317 constexpr typename basic_format_parse_context<_CharT>::iterator
2318 parse(basic_format_parse_context<_CharT>& __pc)
2320 __format::_Spec<_CharT> __spec{};
2321 const auto __last = __pc.end();
2322 auto __first = __pc.begin();
2324 auto __finalize = [this, &__spec] {
2328 auto __finished = [&] {
2329 if (__first == __last || *__first == '}')
2340 __first = __spec._M_parse_fill_and_align(__first, __last);
2344// _GLIBCXX_RESOLVE_LIB_DEFECTS
2345// P2510R3 Formatting pointers
2346#if __cplusplus > 202302L || ! defined __STRICT_ANSI__
2347#define _GLIBCXX_P2518R3 1
2349#define _GLIBCXX_P2518R3 0
2353 __first = __spec._M_parse_zero_fill(__first, __last);
2358 __first = __spec._M_parse_width(__first, __last, __pc);
2360 if (__first != __last)
2362 if (*__first == 'p')
2365 else if (*__first == 'P')
2367 // _GLIBCXX_RESOLVE_LIB_DEFECTS
2368 // P2510R3 Formatting pointers
2369 __spec._M_type = __format::_Pres_P;
2378 __format::__failed_to_parse_format_spec();
2381 template<typename _Out>
2382 typename basic_format_context<_Out, _CharT>::iterator
2383 format(const void* __v, basic_format_context<_Out, _CharT>& __fc) const
2385 auto __u = reinterpret_cast<__UINTPTR_TYPE__>(__v);
2386 char __buf[2 + sizeof(__v) * 2];
2387 auto [__ptr, __ec] = std::to_chars(__buf + 2, std::end(__buf),
2389 int __n = __ptr - __buf;
2393 if (_M_spec._M_type == __format::_Pres_P)
2396 for (auto __p = __buf + 2; __p != __ptr; ++__p)
2397#if __has_builtin(__builtin_toupper)
2398 *__p = __builtin_toupper(*__p);
2400 *__p = std::toupper(*__p);
2405 basic_string_view<_CharT> __str;
2406 if constexpr (is_same_v<_CharT, char>)
2407 __str = string_view(__buf, __n);
2408#ifdef _GLIBCXX_USE_WCHAR_T
2411 auto __p = (_CharT*)__builtin_alloca(__n * sizeof(_CharT));
2412 std::__to_wstring_numeric(__buf, __n, __p);
2413 __str = wstring_view(__p, __n);
2418 if (_M_spec._M_zero_fill)
2420 size_t __width = _M_spec._M_get_width(__fc);
2421 if (__width <= __str.size())
2422 return __format::__write(__fc.out(), __str);
2424 auto __out = __fc.out();
2425 // Write "0x" or "0X" prefix before zero-filling.
2426 __out = __format::__write(std::move(__out), __str.substr(0, 2));
2427 __str.remove_prefix(2);
2428 size_t __nfill = __width - __n;
2429 return __format::__write_padded(std::move(__out), __str,
2430 __format::_Align_right,
2431 __nfill, _CharT('0'));
2435 return __format::__write_padded_as_spec(__str, __n, __fc, _M_spec,
2436 __format::_Align_right);
2440 __format::_Spec<_CharT> _M_spec{};
2443 template<__format::__char _CharT>
2444 struct formatter<void*, _CharT>
2446 formatter() = default;
2448 [[__gnu__::__always_inline__]]
2449 constexpr typename basic_format_parse_context<_CharT>::iterator
2450 parse(basic_format_parse_context<_CharT>& __pc)
2451 { return _M_f.parse(__pc); }
2453 template<typename _Out>
2454 typename basic_format_context<_Out, _CharT>::iterator
2455 format(void* __v, basic_format_context<_Out, _CharT>& __fc) const
2456 { return _M_f.format(__v, __fc); }
2459 formatter<const void*, _CharT> _M_f;
2462 template<__format::__char _CharT>
2463 struct formatter<nullptr_t, _CharT>
2465 formatter() = default;
2467 [[__gnu__::__always_inline__]]
2468 constexpr typename basic_format_parse_context<_CharT>::iterator
2469 parse(basic_format_parse_context<_CharT>& __pc)
2470 { return _M_f.parse(__pc); }
2472 template<typename _Out>
2473 typename basic_format_context<_Out, _CharT>::iterator
2474 format(nullptr_t, basic_format_context<_Out, _CharT>& __fc) const
2475 { return _M_f.format(nullptr, __fc); }
2478 formatter<const void*, _CharT> _M_f;
2482#if defined _GLIBCXX_USE_WCHAR_T && __cpp_lib_format_ranges
2483 // _GLIBCXX_RESOLVE_LIB_DEFECTS
2484 // 3944. Formatters converting sequences of char to sequences of wchar_t
2486 namespace __format { struct __disabled; }
2488 // std::formatter<__disabled, C> uses the primary template, which is disabled.
2490 struct formatter<char*, wchar_t>
2491 : private formatter<__format::__disabled, wchar_t> { };
2493 struct formatter<const char*, wchar_t>
2494 : private formatter<__format::__disabled, wchar_t> { };
2495 template<size_t _Nm>
2496 struct formatter<char[_Nm], wchar_t>
2497 : private formatter<__format::__disabled, wchar_t> { };
2498 template<class _Traits, class _Allocator>
2499 struct formatter<basic_string<char, _Traits, _Allocator>, wchar_t>
2500 : private formatter<__format::__disabled, wchar_t> { };
2501 template<class _Traits>
2502 struct formatter<basic_string_view<char, _Traits>, wchar_t>
2503 : private formatter<__format::__disabled, wchar_t> { };
2506/// @cond undocumented
2509 template<typename _Tp, typename _Context,
2511 = typename _Context::template formatter_type<remove_const_t<_Tp>>,
2512 typename _ParseContext
2513 = basic_format_parse_context<typename _Context::char_type>>
2514 concept __parsable_with
2515 = semiregular<_Formatter>
2516 && requires (_Formatter __f, _ParseContext __pc)
2518 { __f.parse(__pc) } -> same_as<typename _ParseContext::iterator>;
2521 template<typename _Tp, typename _Context,
2523 = typename _Context::template formatter_type<remove_const_t<_Tp>>,
2524 typename _ParseContext
2525 = basic_format_parse_context<typename _Context::char_type>>
2526 concept __formattable_with
2527 = semiregular<_Formatter>
2528 && requires (const _Formatter __cf, _Tp&& __t, _Context __fc)
2530 { __cf.format(__t, __fc) } -> same_as<typename _Context::iterator>;
2533 // An unspecified output iterator type used in the `formattable` concept.
2534 template<typename _CharT>
2535 using _Iter_for = back_insert_iterator<basic_string<_CharT>>;
2537 template<typename _Tp, typename _CharT,
2538 typename _Context = basic_format_context<_Iter_for<_CharT>, _CharT>>
2539 concept __formattable_impl
2540 = __parsable_with<_Tp, _Context> && __formattable_with<_Tp, _Context>;
2542} // namespace __format
2545// Concept std::formattable was introduced by P2286R8 "Formatting Ranges",
2546// but we can't guard it with __cpp_lib_format_ranges until we define that!
2547#if __cplusplus > 202002L
2548 // [format.formattable], concept formattable
2549 template<typename _Tp, typename _CharT>
2551 = __format::__formattable_impl<remove_reference_t<_Tp>, _CharT>;
2554#if __cpp_lib_format_ranges
2555 /// @cond undocumented
2558 template<typename _Rg, typename _CharT>
2559 concept __const_formattable_range
2560 = ranges::input_range<const _Rg>
2561 && formattable<ranges::range_reference_t<const _Rg>, _CharT>;
2563 template<typename _Rg, typename _CharT>
2564 using __maybe_const_range
2565 = conditional_t<__const_formattable_range<_Rg, _CharT>, const _Rg, _Rg>;
2566} // namespace __format
2568#endif // format_ranges
2570 /// An iterator after the last character written, and the number of
2571 /// characters that would have been written.
2572 template<typename _Out>
2573 struct format_to_n_result
2576 iter_difference_t<_Out> size;
2579_GLIBCXX_BEGIN_NAMESPACE_CONTAINER
2580template<typename, typename> class vector;
2581_GLIBCXX_END_NAMESPACE_CONTAINER
2583/// @cond undocumented
2586 template<typename _CharT>
2589 _Sink<_CharT>* _M_sink = nullptr;
2592 using iterator_category = output_iterator_tag;
2593 using value_type = void;
2594 using difference_type = ptrdiff_t;
2595 using pointer = void;
2596 using reference = void;
2598 _Sink_iter() = default;
2599 _Sink_iter(const _Sink_iter&) = default;
2600 _Sink_iter& operator=(const _Sink_iter&) = default;
2602 [[__gnu__::__always_inline__]]
2604 _Sink_iter(_Sink<_CharT>& __sink) : _M_sink(std::addressof(__sink)) { }
2606 [[__gnu__::__always_inline__]]
2607 constexpr _Sink_iter&
2608 operator=(_CharT __c)
2610 _M_sink->_M_write(__c);
2614 [[__gnu__::__always_inline__]]
2615 constexpr _Sink_iter&
2616 operator=(basic_string_view<_CharT> __s)
2618 _M_sink->_M_write(__s);
2622 [[__gnu__::__always_inline__]]
2623 constexpr _Sink_iter&
2624 operator*() { return *this; }
2626 [[__gnu__::__always_inline__]]
2627 constexpr _Sink_iter&
2628 operator++() { return *this; }
2630 [[__gnu__::__always_inline__]]
2631 constexpr _Sink_iter
2632 operator++(int) { return *this; }
2635 _M_reserve(size_t __n) const
2636 { return _M_sink->_M_reserve(__n); }
2639 // Abstract base class for type-erased character sinks.
2640 // All formatting and output is done via this type's iterator,
2641 // to reduce the number of different template instantiations.
2642 template<typename _CharT>
2645 friend class _Sink_iter<_CharT>;
2647 span<_CharT> _M_span;
2648 typename span<_CharT>::iterator _M_next;
2650 // Called when the span is full, to make more space available.
2651 // Precondition: _M_next != _M_span.begin()
2652 // Postcondition: _M_next != _M_span.end()
2653 // TODO: remove the precondition? could make overflow handle it.
2654 virtual void _M_overflow() = 0;
2657 // Precondition: __span.size() != 0
2658 [[__gnu__::__always_inline__]]
2660 _Sink(span<_CharT> __span) noexcept
2661 : _M_span(__span), _M_next(__span.begin())
2664 // The portion of the span that has been written to.
2665 [[__gnu__::__always_inline__]]
2667 _M_used() const noexcept
2668 { return _M_span.first(_M_next - _M_span.begin()); }
2670 // The portion of the span that has not been written to.
2671 [[__gnu__::__always_inline__]]
2672 constexpr span<_CharT>
2673 _M_unused() const noexcept
2674 { return _M_span.subspan(_M_next - _M_span.begin()); }
2676 // Use the start of the span as the next write position.
2677 [[__gnu__::__always_inline__]]
2679 _M_rewind() noexcept
2680 { _M_next = _M_span.begin(); }
2682 // Replace the current output range.
2684 _M_reset(span<_CharT> __s, size_t __pos = 0) noexcept
2687 _M_next = __s.begin() + __pos;
2690 // Called by the iterator for *it++ = c
2692 _M_write(_CharT __c)
2695 if (_M_next - _M_span.begin() == std::ssize(_M_span)) [[unlikely]]
2700 _M_write(basic_string_view<_CharT> __s)
2702 span __to = _M_unused();
2703 while (__to.size() <= __s.size())
2705 __s.copy(__to.data(), __to.size());
2706 _M_next += __to.size();
2707 __s.remove_prefix(__to.size());
2713 __s.copy(__to.data(), __s.size());
2714 _M_next += __s.size();
2718 // A successful _Reservation can be used to directly write
2719 // up to N characters to the sink to avoid unwanted buffering.
2722 // True if the reservation was successful, false otherwise.
2723 explicit operator bool() const noexcept { return _M_sink; }
2724 // A pointer to write directly to the sink.
2725 _CharT* get() const noexcept { return _M_sink->_M_next.operator->(); }
2726 // Add n to the _M_next iterator for the sink.
2727 void _M_bump(size_t __n) { _M_sink->_M_bump(__n); }
2731 // Attempt to reserve space to write n characters to the sink.
2732 // If anything is written to the reservation then there must be a call
2733 // to _M_bump(N2) before any call to another member function of *this,
2734 // where N2 is the number of characters written.
2735 virtual _Reservation
2736 _M_reserve(size_t __n)
2738 if (__n <= _M_unused().size())
2741 if (__n <= _M_span.size()) // Cannot meet the request.
2743 _M_overflow(); // Make more space available.
2744 if (__n <= _M_unused().size())
2750 // Update the next output position after writing directly to the sink.
2751 // pre: no calls to _M_write or _M_overflow since _M_reserve.
2757 _Sink(const _Sink&) = delete;
2758 _Sink& operator=(const _Sink&) = delete;
2760 [[__gnu__::__always_inline__]]
2761 constexpr _Sink_iter<_CharT>
2763 { return _Sink_iter<_CharT>(*this); }
2766 // A sink with an internal buffer. This is used to implement concrete sinks.
2767 template<typename _CharT>
2768 class _Buf_sink : public _Sink<_CharT>
2771 _CharT _M_buf[32 * sizeof(void*) / sizeof(_CharT)];
2773 [[__gnu__::__always_inline__]]
2775 _Buf_sink() noexcept
2776 : _Sink<_CharT>(_M_buf)
2780 using _GLIBCXX_STD_C::vector;
2782 // A sink that fills a sequence (e.g. std::string, std::vector, std::deque).
2783 // Writes to a buffer then appends that to the sequence when it fills up.
2784 template<typename _Seq>
2785 class _Seq_sink final : public _Buf_sink<typename _Seq::value_type>
2787 using _CharT = typename _Seq::value_type;
2791 // Transfer buffer contents to the sequence, so buffer can be refilled.
2793 _M_overflow() override
2795 auto __s = this->_M_used();
2796 if (__s.empty()) [[unlikely]]
2797 return; // Nothing in the buffer to transfer to _M_seq.
2799 // If _M_reserve was called then _M_bump must have been called too.
2800 _GLIBCXX_DEBUG_ASSERT(__s.data() != _M_seq.data());
2802 if constexpr (__is_specialization_of<_Seq, basic_string>)
2803 _M_seq.append(__s.data(), __s.size());
2805 _M_seq.insert(_M_seq.end(), __s.begin(), __s.end());
2807 // Make the whole of _M_buf available for the next write:
2811 typename _Sink<_CharT>::_Reservation
2812 _M_reserve(size_t __n) override
2814 // We might already have n characters available in this->_M_unused(),
2815 // but the whole point of this function is to be an optimization for
2816 // the std::format("{}", x) case. We want to avoid writing to _M_buf
2817 // and then copying that into a basic_string if possible, so this
2818 // function prefers to create space directly in _M_seq rather than
2821 if constexpr (__is_specialization_of<_Seq, basic_string>
2822 || __is_specialization_of<_Seq, vector>)
2824 // Flush the buffer to _M_seq first (should not be needed).
2825 if (this->_M_used().size()) [[unlikely]]
2826 _Seq_sink::_M_overflow();
2828 // Expand _M_seq to make __n new characters available:
2829 const auto __sz = _M_seq.size();
2830 if constexpr (is_same_v<string, _Seq> || is_same_v<wstring, _Seq>)
2831 _M_seq.__resize_and_overwrite(__sz + __n,
2832 [](auto, auto __n2) {
2836 _M_seq.resize(__sz + __n);
2838 // Set _M_used() to be a span over the original part of _M_seq
2839 // and _M_unused() to be the extra capacity we just created:
2840 this->_M_reset(_M_seq, __sz);
2843 else // Try to use the base class' buffer.
2844 return _Sink<_CharT>::_M_reserve(__n);
2848 _M_bump(size_t __n) override
2850 if constexpr (__is_specialization_of<_Seq, basic_string>
2851 || __is_specialization_of<_Seq, vector>)
2853 auto __s = this->_M_used();
2854 _GLIBCXX_DEBUG_ASSERT(__s.data() == _M_seq.data());
2855 // Truncate the sequence to the part that was actually written to:
2856 _M_seq.resize(__s.size() + __n);
2857 // Switch back to using buffer:
2858 this->_M_reset(this->_M_buf);
2863 // TODO: for SSO string, use SSO buffer as initial span, then switch
2864 // to _M_buf if it overflows? Or even do that for all unused capacity?
2866 [[__gnu__::__always_inline__]]
2867 _Seq_sink() noexcept(is_nothrow_default_constructible_v<_Seq>)
2870 _Seq_sink(_Seq&& __s) noexcept(is_nothrow_move_constructible_v<_Seq>)
2871 : _M_seq(std::move(__s))
2874 using _Sink<_CharT>::out;
2879 if (this->_M_used().size() != 0)
2880 _Seq_sink::_M_overflow();
2881 return std::move(_M_seq);
2884 // A writable span that views everything written to the sink.
2885 // Will be either a view over _M_seq or the used part of _M_buf.
2889 auto __s = this->_M_used();
2892 if (__s.size() != 0)
2893 _Seq_sink::_M_overflow();
2900 template<typename _CharT, typename _Alloc = allocator<_CharT>>
2902 = _Seq_sink<basic_string<_CharT, char_traits<_CharT>, _Alloc>>;
2904 // template<typename _CharT, typename _Alloc = allocator<_CharT>>
2905 // using _Vec_sink = _Seq_sink<vector<_CharT, _Alloc>>;
2907 // A sink that writes to an output iterator.
2908 // Writes to a fixed-size buffer and then flushes to the output iterator
2909 // when the buffer fills up.
2910 template<typename _CharT, typename _OutIter>
2911 class _Iter_sink : public _Buf_sink<_CharT>
2914 iter_difference_t<_OutIter> _M_max;
2917 size_t _M_count = 0;
2920 _M_overflow() override
2922 auto __s = this->_M_used();
2923 if (_M_max < 0) // No maximum.
2924 _M_out = ranges::copy(__s, std::move(_M_out)).out;
2925 else if (_M_count < static_cast<size_t>(_M_max))
2927 auto __max = _M_max - _M_count;
2928 span<_CharT> __first;
2929 if (__max < __s.size())
2930 __first = __s.first(static_cast<size_t>(__max));
2933 _M_out = ranges::copy(__first, std::move(_M_out)).out;
2936 _M_count += __s.size();
2940 [[__gnu__::__always_inline__]]
2942 _Iter_sink(_OutIter __out, iter_difference_t<_OutIter> __max = -1)
2943 : _M_out(std::move(__out)), _M_max(__max)
2946 using _Sink<_CharT>::out;
2948 format_to_n_result<_OutIter>
2951 if (this->_M_used().size() != 0)
2952 _Iter_sink::_M_overflow();
2953 iter_difference_t<_OutIter> __count(_M_count);
2954 return { std::move(_M_out), __count };
2958 // Partial specialization for contiguous iterators.
2959 // No buffer is used, characters are written straight to the iterator.
2960 // We do not know the size of the output range, so the span size just grows
2961 // as needed. The end of the span might be an invalid pointer outside the
2962 // valid range, but we never actually call _M_span.end(). This class does
2963 // not introduce any invalid pointer arithmetic or overflows that would not
2964 // have happened anyway.
2965 template<typename _CharT, contiguous_iterator _OutIter>
2966 requires same_as<iter_value_t<_OutIter>, _CharT>
2967 class _Iter_sink<_CharT, _OutIter> : public _Sink<_CharT>
2970 iter_difference_t<_OutIter> _M_max = -1;
2972 size_t _M_count = 0;
2974 _CharT _M_buf[64]; // Write here after outputting _M_max characters.
2978 _M_overflow() override
2980 if (this->_M_unused().size() != 0)
2981 return; // No need to switch to internal buffer yet.
2983 auto __s = this->_M_used();
2987 _M_count += __s.size();
2988 // Span was already sized for the maximum character count,
2989 // if it overflows then any further output must go to the
2990 // internal buffer, to be discarded.
2991 this->_M_reset(this->_M_buf);
2995 // No maximum character count. Just extend the span to allow
2996 // writing more characters to it.
2997 this->_M_reset({__s.data(), __s.size() + 1024}, __s.size());
3001 typename _Sink<_CharT>::_Reservation
3002 _M_reserve(size_t __n) final
3004 auto __avail = this->_M_unused();
3005 if (__n > __avail.size())
3008 return {}; // cannot grow
3010 auto __s = this->_M_used();
3011 this->_M_reset({__s.data(), __s.size() + __n}, __s.size());
3018 _S_make_span(_CharT* __ptr, iter_difference_t<_OutIter> __n,
3019 span<_CharT> __buf) noexcept
3022 return __buf; // Only write to the internal buffer.
3026 if constexpr (!is_integral_v<iter_difference_t<_OutIter>>
3027 || sizeof(__n) > sizeof(size_t))
3029 // __int128 or __detail::__max_diff_type
3030 auto __m = iter_difference_t<_OutIter>((size_t)-1);
3034 return {__ptr, (size_t)__n};
3037#if __has_builtin(__builtin_dynamic_object_size)
3038 if (size_t __bytes = __builtin_dynamic_object_size(__ptr, 2))
3039 return {__ptr, __bytes / sizeof(_CharT)};
3041 // Avoid forming a pointer to a different memory page.
3042 const auto __off = reinterpret_cast<__UINTPTR_TYPE__>(__ptr) % 1024;
3043 __n = (1024 - __off) / sizeof(_CharT);
3044 if (__n > 0) [[likely]]
3045 return {__ptr, static_cast<size_t>(__n)};
3046 else // Misaligned/packed buffer of wchar_t?
3052 _Iter_sink(_OutIter __out, iter_difference_t<_OutIter> __n = -1) noexcept
3053 : _Sink<_CharT>(_S_make_span(std::to_address(__out), __n, _M_buf)),
3054 _M_first(__out), _M_max(__n)
3057 format_to_n_result<_OutIter>
3060 auto __s = this->_M_used();
3061 if (__s.data() == _M_buf)
3063 // Switched to internal buffer, so must have written _M_max.
3064 iter_difference_t<_OutIter> __count(_M_count + __s.size());
3065 return { _M_first + _M_max, __count };
3067 else // Not using internal buffer yet
3069 iter_difference_t<_OutIter> __count(__s.size());
3070 return { _M_first + __count, __count };
3075 enum _Arg_t : unsigned char {
3076 _Arg_none, _Arg_bool, _Arg_c, _Arg_i, _Arg_u, _Arg_ll, _Arg_ull,
3077 _Arg_flt, _Arg_dbl, _Arg_ldbl, _Arg_str, _Arg_sv, _Arg_ptr, _Arg_handle,
3078 _Arg_i128, _Arg_u128,
3079 _Arg_bf16, _Arg_f16, _Arg_f32, _Arg_f64, // These are unused.
3080#ifdef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
3082 _Arg_f128 = _Arg_ldbl,
3083 _Arg_ibm128 = _Arg_next_value_,
3090 template<typename _Context>
3093 using _CharT = typename _Context::char_type;
3109 unsigned long long _M_ull;
3112#ifndef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT // No long double if it's ambiguous.
3113 long double _M_ldbl;
3115 const _CharT* _M_str;
3116 basic_string_view<_CharT> _M_sv;
3118 _HandleBase _M_handle;
3119#ifdef __SIZEOF_INT128__
3121 unsigned __int128 _M_u128;
3123#ifdef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
3126#elif _GLIBCXX_FORMAT_F128 == 2
3127 __float128_t _M_f128;
3131 [[__gnu__::__always_inline__]]
3132 _Arg_value() : _M_none() { }
3135 template<typename _Tp>
3136 _Arg_value(in_place_type_t<_Tp>, _Tp __val)
3137 { _S_get<_Tp>() = __val; }
3140 template<typename _Tp, typename _Self>
3141 [[__gnu__::__always_inline__]]
3143 _S_get(_Self& __u) noexcept
3145 if constexpr (is_same_v<_Tp, bool>)
3147 else if constexpr (is_same_v<_Tp, _CharT>)
3149 else if constexpr (is_same_v<_Tp, int>)
3151 else if constexpr (is_same_v<_Tp, unsigned>)
3153 else if constexpr (is_same_v<_Tp, long long>)
3155 else if constexpr (is_same_v<_Tp, unsigned long long>)
3157 else if constexpr (is_same_v<_Tp, float>)
3159 else if constexpr (is_same_v<_Tp, double>)
3161#ifndef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
3162 else if constexpr (is_same_v<_Tp, long double>)
3165 else if constexpr (is_same_v<_Tp, __ieee128>)
3167 else if constexpr (is_same_v<_Tp, __ibm128>)
3168 return __u._M_ibm128;
3170 else if constexpr (is_same_v<_Tp, const _CharT*>)
3172 else if constexpr (is_same_v<_Tp, basic_string_view<_CharT>>)
3174 else if constexpr (is_same_v<_Tp, const void*>)
3176#ifdef __SIZEOF_INT128__
3177 else if constexpr (is_same_v<_Tp, __int128>)
3179 else if constexpr (is_same_v<_Tp, unsigned __int128>)
3182#if _GLIBCXX_FORMAT_F128 == 2
3183 else if constexpr (is_same_v<_Tp, __float128_t>)
3186 else if constexpr (derived_from<_Tp, _HandleBase>)
3187 return static_cast<_Tp&>(__u._M_handle);
3188 // Otherwise, ill-formed.
3191 template<typename _Tp>
3192 [[__gnu__::__always_inline__]]
3195 { return _S_get<_Tp>(*this); }
3197 template<typename _Tp>
3198 [[__gnu__::__always_inline__]]
3200 _M_get() const noexcept
3201 { return _S_get<_Tp>(*this); }
3203 template<typename _Tp>
3204 [[__gnu__::__always_inline__]]
3206 _M_set(_Tp __v) noexcept
3208 if constexpr (derived_from<_Tp, _HandleBase>)
3209 std::construct_at(&_M_handle, __v);
3211 _S_get<_Tp>(*this) = __v;
3215 // [format.arg.store], class template format-arg-store
3216 template<typename _Context, typename... _Args>
3219} // namespace __format
3222 template<typename _Context>
3223 class basic_format_arg
3225 using _CharT = typename _Context::char_type;
3227 template<typename _Tp>
3228 static constexpr bool __formattable
3229 = __format::__formattable_with<_Tp, _Context>;
3232 class handle : public __format::_Arg_value<_Context>::_HandleBase
3234 using _Base = typename __format::_Arg_value<_Context>::_HandleBase;
3236 // Format as const if possible, to reduce instantiations.
3237 template<typename _Tp>
3238 using __maybe_const_t
3239 = __conditional_t<__formattable<const _Tp>, const _Tp, _Tp>;
3241 template<typename _Tq>
3243 _S_format(basic_format_parse_context<_CharT>& __parse_ctx,
3244 _Context& __format_ctx, const void* __ptr)
3246 using _Td = remove_const_t<_Tq>;
3247 typename _Context::template formatter_type<_Td> __f;
3248 __parse_ctx.advance_to(__f.parse(__parse_ctx));
3249 _Tq& __val = *const_cast<_Tq*>(static_cast<const _Td*>(__ptr));
3250 __format_ctx.advance_to(__f.format(__val, __format_ctx));
3253 template<typename _Tp>
3255 handle(_Tp& __val) noexcept
3257 this->_M_ptr = __builtin_addressof(__val);
3258 auto __func = _S_format<__maybe_const_t<_Tp>>;
3259 this->_M_func = reinterpret_cast<void(*)()>(__func);
3262 friend class basic_format_arg<_Context>;
3265 handle(const handle&) = default;
3266 handle& operator=(const handle&) = default;
3268 [[__gnu__::__always_inline__]]
3270 format(basic_format_parse_context<_CharT>& __pc, _Context& __fc) const
3272 using _Func = void(*)(basic_format_parse_context<_CharT>&,
3273 _Context&, const void*);
3274 auto __f = reinterpret_cast<_Func>(this->_M_func);
3275 __f(__pc, __fc, this->_M_ptr);
3279 [[__gnu__::__always_inline__]]
3280 basic_format_arg() noexcept : _M_type(__format::_Arg_none) { }
3282 [[nodiscard,__gnu__::__always_inline__]]
3283 explicit operator bool() const noexcept
3284 { return _M_type != __format::_Arg_none; }
3287 template<typename _Ctx>
3288 friend class basic_format_args;
3290 template<typename _Ctx, typename... _Args>
3291 friend class __format::_Arg_store;
3293 static_assert(is_trivially_copyable_v<__format::_Arg_value<_Context>>);
3295 __format::_Arg_value<_Context> _M_val;
3296 __format::_Arg_t _M_type;
3298 // Transform incoming argument type to the type stored in _Arg_value.
3299 // e.g. short -> int, std::string -> std::string_view,
3300 // char[3] -> const char*.
3301 template<typename _Tp>
3302 static consteval auto
3305 using _Td = remove_const_t<_Tp>;
3306 if constexpr (is_same_v<_Td, bool>)
3307 return type_identity<bool>();
3308 else if constexpr (is_same_v<_Td, _CharT>)
3309 return type_identity<_CharT>();
3310 else if constexpr (is_same_v<_Td, char> && is_same_v<_CharT, wchar_t>)
3311 return type_identity<_CharT>();
3312#ifdef __SIZEOF_INT128__ // Check before signed/unsigned integer
3313 else if constexpr (is_same_v<_Td, __int128>)
3314 return type_identity<__int128>();
3315 else if constexpr (is_same_v<_Td, unsigned __int128>)
3316 return type_identity<unsigned __int128>();
3318 else if constexpr (__is_signed_integer<_Td>::value)
3320 if constexpr (sizeof(_Td) <= sizeof(int))
3321 return type_identity<int>();
3322 else if constexpr (sizeof(_Td) <= sizeof(long long))
3323 return type_identity<long long>();
3325 else if constexpr (__is_unsigned_integer<_Td>::value)
3327 if constexpr (sizeof(_Td) <= sizeof(unsigned))
3328 return type_identity<unsigned>();
3329 else if constexpr (sizeof(_Td) <= sizeof(unsigned long long))
3330 return type_identity<unsigned long long>();
3332 else if constexpr (is_same_v<_Td, float>)
3333 return type_identity<float>();
3334 else if constexpr (is_same_v<_Td, double>)
3335 return type_identity<double>();
3336#ifndef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
3337 else if constexpr (is_same_v<_Td, long double>)
3338 return type_identity<long double>();
3340 else if constexpr (is_same_v<_Td, __ibm128>)
3341 return type_identity<__ibm128>();
3342 else if constexpr (is_same_v<_Td, __ieee128>)
3343 return type_identity<__ieee128>();
3346#if defined(__FLT16_DIG__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
3347 else if constexpr (is_same_v<_Td, _Float16>)
3348 return type_identity<float>();
3351#if defined(__BFLT16_DIG__) && defined(_GLIBCXX_FLOAT_IS_IEEE_BINARY32)
3352 else if constexpr (is_same_v<_Td, decltype(0.0bf16)>)
3353 return type_identity<float>();
3357 else if constexpr (is_same_v<_Td, _Float32>)
3358# ifdef _GLIBCXX_FLOAT_IS_IEEE_BINARY32
3359 return type_identity<float>();
3361 return type_identity<_Float32>();
3365 else if constexpr (is_same_v<_Td, _Float64>)
3366# ifdef _GLIBCXX_DOUBLE_IS_IEEE_BINARY64
3367 return type_identity<double>();
3369 return type_identity<_Float64>();
3372#if _GLIBCXX_FORMAT_F128
3374 else if constexpr (is_same_v<_Td, _Float128>)
3375 return type_identity<__format::__float128_t>();
3377# if __SIZEOF_FLOAT128__
3378 else if constexpr (is_same_v<_Td, __float128>)
3379 return type_identity<__format::__float128_t>();
3382 else if constexpr (__is_specialization_of<_Td, basic_string_view>
3383 || __is_specialization_of<_Td, basic_string>)
3385 if constexpr (is_same_v<typename _Td::value_type, _CharT>)
3386 return type_identity<basic_string_view<_CharT>>();
3388 return type_identity<handle>();
3390 else if constexpr (is_same_v<decay_t<_Td>, const _CharT*>)
3391 return type_identity<const _CharT*>();
3392 else if constexpr (is_same_v<decay_t<_Td>, _CharT*>)
3393 return type_identity<const _CharT*>();
3394 else if constexpr (is_void_v<remove_pointer_t<_Td>>)
3395 return type_identity<const void*>();
3396 else if constexpr (is_same_v<_Td, nullptr_t>)
3397 return type_identity<const void*>();
3399 return type_identity<handle>();
3402 // Transform a formattable type to the appropriate storage type.
3403 template<typename _Tp>
3404 using _Normalize = typename decltype(_S_to_arg_type<_Tp>())::type;
3406 // Get the _Arg_t value corresponding to a normalized type.
3407 template<typename _Tp>
3408 static consteval __format::_Arg_t
3411 using namespace __format;
3412 if constexpr (is_same_v<_Tp, bool>)
3414 else if constexpr (is_same_v<_Tp, _CharT>)
3416 else if constexpr (is_same_v<_Tp, int>)
3418 else if constexpr (is_same_v<_Tp, unsigned>)
3420 else if constexpr (is_same_v<_Tp, long long>)
3422 else if constexpr (is_same_v<_Tp, unsigned long long>)
3424 else if constexpr (is_same_v<_Tp, float>)
3426 else if constexpr (is_same_v<_Tp, double>)
3428#ifndef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
3429 else if constexpr (is_same_v<_Tp, long double>)
3432 // Don't use _Arg_ldbl for this target, it's ambiguous.
3433 else if constexpr (is_same_v<_Tp, __ibm128>)
3435 else if constexpr (is_same_v<_Tp, __ieee128>)
3438 else if constexpr (is_same_v<_Tp, const _CharT*>)
3440 else if constexpr (is_same_v<_Tp, basic_string_view<_CharT>>)
3442 else if constexpr (is_same_v<_Tp, const void*>)
3444#ifdef __SIZEOF_INT128__
3445 else if constexpr (is_same_v<_Tp, __int128>)
3447 else if constexpr (is_same_v<_Tp, unsigned __int128>)
3451 // N.B. some of these types will never actually be used here,
3452 // because they get normalized to a standard floating-point type.
3453#if defined __FLT32_DIG__ && ! _GLIBCXX_FLOAT_IS_IEEE_BINARY32
3454 else if constexpr (is_same_v<_Tp, _Float32>)
3457#if defined __FLT64_DIG__ && ! _GLIBCXX_DOUBLE_IS_IEEE_BINARY64
3458 else if constexpr (is_same_v<_Tp, _Float64>)
3461#if _GLIBCXX_FORMAT_F128 == 2
3462 else if constexpr (is_same_v<_Tp, __format::__float128_t>)
3465 else if constexpr (is_same_v<_Tp, handle>)
3469 template<typename _Tp>
3471 _M_set(_Tp __v) noexcept
3473 _M_type = _S_to_enum<_Tp>();
3477 template<typename _Tp>
3478 requires __format::__formattable_with<_Tp, _Context>
3480 basic_format_arg(_Tp& __v) noexcept
3482 using _Td = _Normalize<_Tp>;
3483 if constexpr (is_same_v<_Td, basic_string_view<_CharT>>)
3484 _M_set(_Td{__v.data(), __v.size()});
3485 else if constexpr (is_same_v<remove_const_t<_Tp>, char>
3486 && is_same_v<_CharT, wchar_t>)
3487 _M_set(static_cast<_Td>(static_cast<unsigned char>(__v)));
3489 _M_set(static_cast<_Td>(__v));
3492 template<typename _Ctx, typename... _Argz>
3494 make_format_args(_Argz&...) noexcept;
3496 template<typename _Visitor, typename _Ctx>
3497 friend decltype(auto)
3498 visit_format_arg(_Visitor&& __vis, basic_format_arg<_Ctx>);
3500 template<typename _Visitor>
3502 _M_visit(_Visitor&& __vis, __format::_Arg_t __type)
3504 using namespace __format;
3508 return std::forward<_Visitor>(__vis)(_M_val._M_none);
3510 return std::forward<_Visitor>(__vis)(_M_val._M_bool);
3512 return std::forward<_Visitor>(__vis)(_M_val._M_c);
3514 return std::forward<_Visitor>(__vis)(_M_val._M_i);
3516 return std::forward<_Visitor>(__vis)(_M_val._M_u);
3518 return std::forward<_Visitor>(__vis)(_M_val._M_ll);
3520 return std::forward<_Visitor>(__vis)(_M_val._M_ull);
3521#if __glibcxx_to_chars // FIXME: need to be able to format these types!
3523 return std::forward<_Visitor>(__vis)(_M_val._M_flt);
3525 return std::forward<_Visitor>(__vis)(_M_val._M_dbl);
3526#ifndef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
3528 return std::forward<_Visitor>(__vis)(_M_val._M_ldbl);
3531 return std::forward<_Visitor>(__vis)(_M_val._M_f128);
3533 return std::forward<_Visitor>(__vis)(_M_val._M_ibm128);
3537 return std::forward<_Visitor>(__vis)(_M_val._M_str);
3539 return std::forward<_Visitor>(__vis)(_M_val._M_sv);
3541 return std::forward<_Visitor>(__vis)(_M_val._M_ptr);
3544 auto& __h = static_cast<handle&>(_M_val._M_handle);
3545 return std::forward<_Visitor>(__vis)(__h);
3547#ifdef __SIZEOF_INT128__
3549 return std::forward<_Visitor>(__vis)(_M_val._M_i128);
3551 return std::forward<_Visitor>(__vis)(_M_val._M_u128);
3554#if _GLIBCXX_FORMAT_F128 == 2
3556 return std::forward<_Visitor>(__vis)(_M_val._M_f128);
3561 __builtin_unreachable();
3566 template<typename _Visitor, typename _Context>
3567 inline decltype(auto)
3568 visit_format_arg(_Visitor&& __vis, basic_format_arg<_Context> __arg)
3570 return __arg._M_visit(std::forward<_Visitor>(__vis), __arg._M_type);
3573/// @cond undocumented
3576 struct _WidthPrecVisitor
3578 template<typename _Tp>
3580 operator()(_Tp& __arg) const
3582 if constexpr (is_same_v<_Tp, monostate>)
3583 __format::__invalid_arg_id_in_format_string();
3584 // _GLIBCXX_RESOLVE_LIB_DEFECTS
3585 // 3720. Restrict the valid types of arg-id for width and precision
3586 // 3721. Allow an arg-id with a value of zero for width
3587 else if constexpr (sizeof(_Tp) <= sizeof(long long))
3589 // _GLIBCXX_RESOLVE_LIB_DEFECTS
3590 // 3720. Restrict the valid types of arg-id for width and precision
3591 if constexpr (__is_unsigned_integer<_Tp>::value)
3593 else if constexpr (__is_signed_integer<_Tp>::value)
3597 __throw_format_error("format error: argument used for width or "
3598 "precision must be a non-negative integer");
3602 template<typename _Context>
3604 __int_from_arg(const basic_format_arg<_Context>& __arg)
3605 { return std::visit_format_arg(_WidthPrecVisitor(), __arg); }
3607 // Pack _Arg_t enum values into a single 60-bit integer.
3608 template<int _Bits, size_t _Nm>
3610 __pack_arg_types(const array<_Arg_t, _Nm>& __types)
3612 __UINT64_TYPE__ __packed_types = 0;
3613 for (auto __i = __types.rbegin(); __i != __types.rend(); ++__i)
3614 __packed_types = (__packed_types << _Bits) | *__i;
3615 return __packed_types;
3617} // namespace __format
3620 template<typename _Context>
3621 class basic_format_args
3623 static constexpr int _S_packed_type_bits = 5; // _Arg_t values [0,20]
3624 static constexpr int _S_packed_type_mask = 0b11111;
3625 static constexpr int _S_max_packed_args = 12;
3627 static_assert( __format::_Arg_max_ <= (1 << _S_packed_type_bits) );
3629 template<typename... _Args>
3630 using _Store = __format::_Arg_store<_Context, _Args...>;
3632 template<typename _Ctx, typename... _Args>
3633 friend class __format::_Arg_store;
3635 using uint64_t = __UINT64_TYPE__;
3636 using _Format_arg = basic_format_arg<_Context>;
3637 using _Format_arg_val = __format::_Arg_value<_Context>;
3639 // If args are packed then the number of args is in _M_packed_size and
3640 // the packed types are in _M_unpacked_size, accessed via _M_type(i).
3641 // If args are not packed then the number of args is in _M_unpacked_size
3642 // and _M_packed_size is zero.
3643 uint64_t _M_packed_size : 4;
3644 uint64_t _M_unpacked_size : 60;
3647 const _Format_arg_val* _M_values; // Active when _M_packed_size != 0
3648 const _Format_arg* _M_args; // Active when _M_packed_size == 0
3652 _M_size() const noexcept
3653 { return _M_packed_size ? _M_packed_size : _M_unpacked_size; }
3655 typename __format::_Arg_t
3656 _M_type(size_t __i) const noexcept
3658 uint64_t __t = _M_unpacked_size >> (__i * _S_packed_type_bits);
3659 return static_cast<__format::_Arg_t>(__t & _S_packed_type_mask);
3662 template<typename _Ctx, typename... _Args>
3664 make_format_args(_Args&...) noexcept;
3666 // An array of _Arg_t enums corresponding to _Args...
3667 template<typename... _Args>
3668 static consteval array<__format::_Arg_t, sizeof...(_Args)>
3670 { return {_Format_arg::template _S_to_enum<_Args>()...}; }
3673 template<typename... _Args>
3674 basic_format_args(const _Store<_Args...>& __store) noexcept;
3676 [[nodiscard,__gnu__::__always_inline__]]
3677 basic_format_arg<_Context>
3678 get(size_t __i) const noexcept
3680 basic_format_arg<_Context> __arg;
3681 if (__i < _M_packed_size)
3683 __arg._M_type = _M_type(__i);
3684 __arg._M_val = _M_values[__i];
3686 else if (_M_packed_size == 0 && __i < _M_unpacked_size)
3687 __arg = _M_args[__i];
3692 // _GLIBCXX_RESOLVE_LIB_DEFECTS
3693 // 3810. CTAD for std::basic_format_args
3694 template<typename _Context, typename... _Args>
3695 basic_format_args(__format::_Arg_store<_Context, _Args...>)
3696 -> basic_format_args<_Context>;
3698 template<typename _Context, typename... _Args>
3700 make_format_args(_Args&... __fmt_args) noexcept;
3702 // An array of type-erased formatting arguments.
3703 template<typename _Context, typename... _Args>
3704 class __format::_Arg_store
3706 friend std::basic_format_args<_Context>;
3708 template<typename _Ctx, typename... _Argz>
3710#if _GLIBCXX_INLINE_VERSION
3711 __8:: // Needed for PR c++/59256
3713 make_format_args(_Argz&...) noexcept;
3715 // For a sufficiently small number of arguments we only store values.
3716 // basic_format_args can get the types from the _Args pack.
3717 static constexpr bool _S_values_only
3718 = sizeof...(_Args) <= basic_format_args<_Context>::_S_max_packed_args;
3721 = __conditional_t<_S_values_only,
3722 __format::_Arg_value<_Context>,
3723 basic_format_arg<_Context>>;
3725 _Element_t _M_args[sizeof...(_Args)];
3727 template<typename _Tp>
3729 _S_make_elt(_Tp& __v)
3731 using _Tq = remove_const_t<_Tp>;
3732 using _CharT = typename _Context::char_type;
3733 static_assert(is_default_constructible_v<formatter<_Tq, _CharT>>,
3734 "std::formatter must be specialized for the type "
3735 "of each format arg");
3736 using __format::__formattable_with;
3737 if constexpr (is_const_v<_Tp>)
3738 if constexpr (!__formattable_with<_Tp, _Context>)
3739 if constexpr (__formattable_with<_Tq, _Context>)
3740 static_assert(__formattable_with<_Tp, _Context>,
3741 "format arg must be non-const because its "
3742 "std::formatter specialization has a "
3743 "non-const reference parameter");
3744 basic_format_arg<_Context> __arg(__v);
3745 if constexpr (_S_values_only)
3746 return __arg._M_val;
3751 template<typename... _Tp>
3752 requires (sizeof...(_Tp) == sizeof...(_Args))
3753 [[__gnu__::__always_inline__]]
3754 _Arg_store(_Tp&... __a) noexcept
3755 : _M_args{_S_make_elt(__a)...}
3759 template<typename _Context>
3760 class __format::_Arg_store<_Context>
3763 template<typename _Context>
3764 template<typename... _Args>
3766 basic_format_args<_Context>::
3767 basic_format_args(const _Store<_Args...>& __store) noexcept
3769 if constexpr (sizeof...(_Args) == 0)
3772 _M_unpacked_size = 0;
3775 else if constexpr (sizeof...(_Args) <= _S_max_packed_args)
3777 // The number of packed arguments:
3778 _M_packed_size = sizeof...(_Args);
3779 // The packed type enums:
3781 = __format::__pack_arg_types<_S_packed_type_bits>(_S_types_to_pack<_Args...>());
3782 // The _Arg_value objects.
3783 _M_values = __store._M_args;
3787 // No packed arguments:
3789 // The number of unpacked arguments:
3790 _M_unpacked_size = sizeof...(_Args);
3791 // The basic_format_arg objects:
3792 _M_args = __store._M_args;
3796 /// Capture formatting arguments for use by `std::vformat`.
3797 template<typename _Context = format_context, typename... _Args>
3798 [[nodiscard,__gnu__::__always_inline__]]
3800 make_format_args(_Args&... __fmt_args) noexcept
3802 using _Fmt_arg = basic_format_arg<_Context>;
3803 using _Store = __format::_Arg_store<_Context, typename _Fmt_arg::template
3804 _Normalize<_Args>...>;
3805 return _Store(__fmt_args...);
3808#ifdef _GLIBCXX_USE_WCHAR_T
3809 /// Capture formatting arguments for use by `std::vformat` (for wide output).
3810 template<typename... _Args>
3811 [[nodiscard,__gnu__::__always_inline__]]
3813 make_wformat_args(_Args&... __args) noexcept
3814 { return std::make_format_args<wformat_context>(__args...); }
3817/// @cond undocumented
3820 template<typename _Out, typename _CharT, typename _Context>
3822 __do_vformat_to(_Out, basic_string_view<_CharT>,
3823 const basic_format_args<_Context>&,
3824 const locale* = nullptr);
3825} // namespace __format
3828 /** Context for std::format and similar functions.
3830 * A formatting context contains an output iterator and locale to use
3831 * for the formatting operations. Most programs will never need to use
3832 * this class template explicitly. For typical uses of `std::format` the
3833 * library will use the specializations `std::format_context` (for `char`)
3834 * and `std::wformat_context` (for `wchar_t`).
3836 template<typename _Out, typename _CharT>
3837 class basic_format_context
3839 static_assert( output_iterator<_Out, const _CharT&> );
3841 basic_format_args<basic_format_context> _M_args;
3843 __format::_Optional_locale _M_loc;
3845 basic_format_context(basic_format_args<basic_format_context> __args,
3847 : _M_args(__args), _M_out(std::move(__out))
3850 basic_format_context(basic_format_args<basic_format_context> __args,
3851 _Out __out, const std::locale& __loc)
3852 : _M_args(__args), _M_out(std::move(__out)), _M_loc(__loc)
3855 // _GLIBCXX_RESOLVE_LIB_DEFECTS
3856 // 4061. Should std::basic_format_context be
3857 // default-constructible/copyable/movable?
3858 basic_format_context(const basic_format_context&) = delete;
3859 basic_format_context& operator=(const basic_format_context&) = delete;
3861 template<typename _Out2, typename _CharT2, typename _Context2>
3863 __format::__do_vformat_to(_Out2, basic_string_view<_CharT2>,
3864 const basic_format_args<_Context2>&,
3868 ~basic_format_context() = default;
3870 using iterator = _Out;
3871 using char_type = _CharT;
3872 template<typename _Tp>
3873 using formatter_type = formatter<_Tp, _CharT>;
3876 basic_format_arg<basic_format_context>
3877 arg(size_t __id) const noexcept
3878 { return _M_args.get(__id); }
3881 std::locale locale() { return _M_loc.value(); }
3884 iterator out() { return std::move(_M_out); }
3886 void advance_to(iterator __it) { _M_out = std::move(__it); }
3890/// @cond undocumented
3893 // Abstract base class defining an interface for scanning format strings.
3894 // Scan the characters in a format string, dividing it up into strings of
3895 // ordinary characters, escape sequences, and replacement fields.
3896 // Call virtual functions for derived classes to parse format-specifiers
3897 // or write formatted output.
3898 template<typename _CharT>
3901 using iterator = typename basic_format_parse_context<_CharT>::iterator;
3903 basic_format_parse_context<_CharT> _M_pc;
3906 _Scanner(basic_string_view<_CharT> __str, size_t __nargs = -1)
3907 : _M_pc(__str, __nargs)
3910 constexpr iterator begin() const noexcept { return _M_pc.begin(); }
3911 constexpr iterator end() const noexcept { return _M_pc.end(); }
3916 basic_string_view<_CharT> __fmt = _M_fmt_str();
3918 if (__fmt.size() == 2 && __fmt[0] == '{' && __fmt[1] == '}')
3920 _M_pc.advance_to(begin() + 1);
3921 _M_format_arg(_M_pc.next_arg_id());
3925 size_t __lbr = __fmt.find('{');
3926 size_t __rbr = __fmt.find('}');
3928 while (__fmt.size())
3930 auto __cmp = __lbr <=> __rbr;
3934 _M_pc.advance_to(end());
3939 if (__lbr + 1 == __fmt.size()
3940 || (__rbr == __fmt.npos && __fmt[__lbr + 1] != '{'))
3941 __format::__unmatched_left_brace_in_format_string();
3942 const bool __is_escape = __fmt[__lbr + 1] == '{';
3943 iterator __last = begin() + __lbr + int(__is_escape);
3944 _M_on_chars(__last);
3945 _M_pc.advance_to(__last + 1);
3946 __fmt = _M_fmt_str();
3949 if (__rbr != __fmt.npos)
3951 __lbr = __fmt.find('{');
3955 _M_on_replacement_field();
3956 __fmt = _M_fmt_str();
3957 __lbr = __fmt.find('{');
3958 __rbr = __fmt.find('}');
3963 if (++__rbr == __fmt.size() || __fmt[__rbr] != '}')
3964 __format::__unmatched_right_brace_in_format_string();
3965 iterator __last = begin() + __rbr;
3966 _M_on_chars(__last);
3967 _M_pc.advance_to(__last + 1);
3968 __fmt = _M_fmt_str();
3969 if (__lbr != __fmt.npos)
3971 __rbr = __fmt.find('}');
3976 constexpr basic_string_view<_CharT>
3977 _M_fmt_str() const noexcept
3978 { return {begin(), end()}; }
3980 constexpr virtual void _M_on_chars(iterator) { }
3982 constexpr void _M_on_replacement_field()
3984 auto __next = begin();
3988 __id = _M_pc.next_arg_id();
3989 else if (*__next == ':')
3991 __id = _M_pc.next_arg_id();
3992 _M_pc.advance_to(++__next);
3996 auto [__i, __ptr] = __format::__parse_arg_id(begin(), end());
3997 if (!__ptr || !(*__ptr == '}' || *__ptr == ':'))
3998 __format::__invalid_arg_id_in_format_string();
3999 _M_pc.check_arg_id(__id = __i);
4002 _M_pc.advance_to(++__ptr);
4005 _M_pc.advance_to(__ptr);
4007 _M_format_arg(__id);
4008 if (begin() == end() || *begin() != '}')
4009 __format::__unmatched_left_brace_in_format_string();
4010 _M_pc.advance_to(begin() + 1); // Move past '}'
4013 constexpr virtual void _M_format_arg(size_t __id) = 0;
4016 // Process a format string and format the arguments in the context.
4017 template<typename _Out, typename _CharT>
4018 class _Formatting_scanner : public _Scanner<_CharT>
4021 _Formatting_scanner(basic_format_context<_Out, _CharT>& __fc,
4022 basic_string_view<_CharT> __str)
4023 : _Scanner<_CharT>(__str), _M_fc(__fc)
4027 basic_format_context<_Out, _CharT>& _M_fc;
4029 using iterator = typename _Scanner<_CharT>::iterator;
4032 _M_on_chars(iterator __last) override
4034 basic_string_view<_CharT> __str(this->begin(), __last);
4035 _M_fc.advance_to(__format::__write(_M_fc.out(), __str));
4039 _M_format_arg(size_t __id) override
4041 using _Context = basic_format_context<_Out, _CharT>;
4042 using handle = typename basic_format_arg<_Context>::handle;
4044 std::visit_format_arg([this](auto& __arg) {
4045 using _Type = remove_reference_t<decltype(__arg)>;
4046 using _Formatter = typename _Context::template formatter_type<_Type>;
4047 if constexpr (is_same_v<_Type, monostate>)
4048 __format::__invalid_arg_id_in_format_string();
4049 else if constexpr (is_same_v<_Type, handle>)
4050 __arg.format(this->_M_pc, this->_M_fc);
4051 else if constexpr (is_default_constructible_v<_Formatter>)
4054 this->_M_pc.advance_to(__f.parse(this->_M_pc));
4055 this->_M_fc.advance_to(__f.format(__arg, this->_M_fc));
4058 static_assert(__format::__formattable_with<_Type, _Context>);
4059 }, _M_fc.arg(__id));
4063 // Validate a format string for Args.
4064 template<typename _CharT, typename... _Args>
4065 class _Checking_scanner : public _Scanner<_CharT>
4068 (is_default_constructible_v<formatter<_Args, _CharT>> && ...),
4069 "std::formatter must be specialized for each type being formatted");
4073 _Checking_scanner(basic_string_view<_CharT> __str)
4074 : _Scanner<_CharT>(__str, sizeof...(_Args))
4079 _M_format_arg(size_t __id) override
4081 if constexpr (sizeof...(_Args) != 0)
4083 if (__id < sizeof...(_Args))
4085 _M_parse_format_spec<_Args...>(__id);
4089 __builtin_unreachable();
4092 template<typename _Tp, typename... _OtherArgs>
4094 _M_parse_format_spec(size_t __id)
4098 formatter<_Tp, _CharT> __f;
4099 this->_M_pc.advance_to(__f.parse(this->_M_pc));
4101 else if constexpr (sizeof...(_OtherArgs) != 0)
4102 _M_parse_format_spec<_OtherArgs...>(__id - 1);
4104 __builtin_unreachable();
4108 template<typename _Out, typename _CharT, typename _Context>
4110 __do_vformat_to(_Out __out, basic_string_view<_CharT> __fmt,
4111 const basic_format_args<_Context>& __args,
4112 const locale* __loc)
4114 _Iter_sink<_CharT, _Out> __sink(std::move(__out));
4115 _Sink_iter<_CharT> __sink_out;
4117 if constexpr (is_same_v<_Out, _Sink_iter<_CharT>>)
4118 __sink_out = __out; // Already a sink iterator, safe to use post-move.
4120 __sink_out = __sink.out();
4122 if constexpr (is_same_v<_CharT, char>)
4123 // Fast path for "{}" format strings and simple format arg types.
4124 if (__fmt.size() == 2 && __fmt[0] == '{' && __fmt[1] == '}')
4126 bool __done = false;
4127 std::visit_format_arg([&](auto& __arg) {
4128 using _Tp = remove_cvref_t<decltype(__arg)>;
4129 if constexpr (is_same_v<_Tp, bool>)
4131 size_t __len = 4 + !__arg;
4132 const char* __chars[] = { "false", "true" };
4133 if (auto __res = __sink_out._M_reserve(__len))
4135 __builtin_memcpy(__res.get(), __chars[__arg], __len);
4136 __res._M_bump(__len);
4140 else if constexpr (is_same_v<_Tp, char>)
4142 if (auto __res = __sink_out._M_reserve(1))
4144 *__res.get() = __arg;
4149 else if constexpr (is_integral_v<_Tp>)
4151 make_unsigned_t<_Tp> __uval;
4152 const bool __neg = __arg < 0;
4154 __uval = make_unsigned_t<_Tp>(~__arg) + 1u;
4157 const auto __n = __detail::__to_chars_len(__uval);
4158 if (auto __res = __sink_out._M_reserve(__n + __neg))
4160 auto __ptr = __res.get();
4162 __detail::__to_chars_10_impl(__ptr + (int)__neg, __n,
4164 __res._M_bump(__n + __neg);
4168 else if constexpr (is_convertible_v<_Tp, string_view>)
4170 string_view __sv = __arg;
4171 if (auto __res = __sink_out._M_reserve(__sv.size()))
4173 __builtin_memcpy(__res.get(), __sv.data(), __sv.size());
4174 __res._M_bump(__sv.size());
4182 if constexpr (is_same_v<_Out, _Sink_iter<_CharT>>)
4185 return std::move(__sink)._M_finish().out;
4189 auto __ctx = __loc == nullptr
4190 ? _Context(__args, __sink_out)
4191 : _Context(__args, __sink_out, *__loc);
4192 _Formatting_scanner<_Sink_iter<_CharT>, _CharT> __scanner(__ctx, __fmt);
4193 __scanner._M_scan();
4195 if constexpr (is_same_v<_Out, _Sink_iter<_CharT>>)
4198 return std::move(__sink)._M_finish().out;
4201} // namespace __format
4204 template<typename _CharT, typename... _Args>
4205 template<typename _Tp>
4206 requires convertible_to<const _Tp&, basic_string_view<_CharT>>
4208 basic_format_string<_CharT, _Args...>::
4209 basic_format_string(const _Tp& __s)
4212 __format::_Checking_scanner<_CharT, remove_cvref_t<_Args>...>
4214 __scanner._M_scan();
4217 // [format.functions], formatting functions
4219 template<typename _Out> requires output_iterator<_Out, const char&>
4220 [[__gnu__::__always_inline__]]
4222 vformat_to(_Out __out, string_view __fmt, format_args __args)
4223 { return __format::__do_vformat_to(std::move(__out), __fmt, __args); }
4225#ifdef _GLIBCXX_USE_WCHAR_T
4226 template<typename _Out> requires output_iterator<_Out, const wchar_t&>
4227 [[__gnu__::__always_inline__]]
4229 vformat_to(_Out __out, wstring_view __fmt, wformat_args __args)
4230 { return __format::__do_vformat_to(std::move(__out), __fmt, __args); }
4233 template<typename _Out> requires output_iterator<_Out, const char&>
4234 [[__gnu__::__always_inline__]]
4236 vformat_to(_Out __out, const locale& __loc, string_view __fmt,
4239 return __format::__do_vformat_to(std::move(__out), __fmt, __args, &__loc);
4242#ifdef _GLIBCXX_USE_WCHAR_T
4243 template<typename _Out> requires output_iterator<_Out, const wchar_t&>
4244 [[__gnu__::__always_inline__]]
4246 vformat_to(_Out __out, const locale& __loc, wstring_view __fmt,
4247 wformat_args __args)
4249 return __format::__do_vformat_to(std::move(__out), __fmt, __args, &__loc);
4255 vformat(string_view __fmt, format_args __args)
4257 __format::_Str_sink<char> __buf;
4258 std::vformat_to(__buf.out(), __fmt, __args);
4259 return std::move(__buf).get();
4262#ifdef _GLIBCXX_USE_WCHAR_T
4265 vformat(wstring_view __fmt, wformat_args __args)
4267 __format::_Str_sink<wchar_t> __buf;
4268 std::vformat_to(__buf.out(), __fmt, __args);
4269 return std::move(__buf).get();
4275 vformat(const locale& __loc, string_view __fmt, format_args __args)
4277 __format::_Str_sink<char> __buf;
4278 std::vformat_to(__buf.out(), __loc, __fmt, __args);
4279 return std::move(__buf).get();
4282#ifdef _GLIBCXX_USE_WCHAR_T
4285 vformat(const locale& __loc, wstring_view __fmt, wformat_args __args)
4287 __format::_Str_sink<wchar_t> __buf;
4288 std::vformat_to(__buf.out(), __loc, __fmt, __args);
4289 return std::move(__buf).get();
4293 template<typename... _Args>
4296 format(format_string<_Args...> __fmt, _Args&&... __args)
4297 { return std::vformat(__fmt.get(), std::make_format_args(__args...)); }
4299#ifdef _GLIBCXX_USE_WCHAR_T
4300 template<typename... _Args>
4303 format(wformat_string<_Args...> __fmt, _Args&&... __args)
4304 { return std::vformat(__fmt.get(), std::make_wformat_args(__args...)); }
4307 template<typename... _Args>
4310 format(const locale& __loc, format_string<_Args...> __fmt,
4313 return std::vformat(__loc, __fmt.get(),
4314 std::make_format_args(__args...));
4317#ifdef _GLIBCXX_USE_WCHAR_T
4318 template<typename... _Args>
4321 format(const locale& __loc, wformat_string<_Args...> __fmt,
4324 return std::vformat(__loc, __fmt.get(),
4325 std::make_wformat_args(__args...));
4329 template<typename _Out, typename... _Args>
4330 requires output_iterator<_Out, const char&>
4332 format_to(_Out __out, format_string<_Args...> __fmt, _Args&&... __args)
4334 return std::vformat_to(std::move(__out), __fmt.get(),
4335 std::make_format_args(__args...));
4338#ifdef _GLIBCXX_USE_WCHAR_T
4339 template<typename _Out, typename... _Args>
4340 requires output_iterator<_Out, const wchar_t&>
4342 format_to(_Out __out, wformat_string<_Args...> __fmt, _Args&&... __args)
4344 return std::vformat_to(std::move(__out), __fmt.get(),
4345 std::make_wformat_args(__args...));
4349 template<typename _Out, typename... _Args>
4350 requires output_iterator<_Out, const char&>
4352 format_to(_Out __out, const locale& __loc, format_string<_Args...> __fmt,
4355 return std::vformat_to(std::move(__out), __loc, __fmt.get(),
4356 std::make_format_args(__args...));
4359#ifdef _GLIBCXX_USE_WCHAR_T
4360 template<typename _Out, typename... _Args>
4361 requires output_iterator<_Out, const wchar_t&>
4363 format_to(_Out __out, const locale& __loc, wformat_string<_Args...> __fmt,
4366 return std::vformat_to(std::move(__out), __loc, __fmt.get(),
4367 std::make_wformat_args(__args...));
4371 template<typename _Out, typename... _Args>
4372 requires output_iterator<_Out, const char&>
4373 inline format_to_n_result<_Out>
4374 format_to_n(_Out __out, iter_difference_t<_Out> __n,
4375 format_string<_Args...> __fmt, _Args&&... __args)
4377 __format::_Iter_sink<char, _Out> __sink(std::move(__out), __n);
4378 std::vformat_to(__sink.out(), __fmt.get(),
4379 std::make_format_args(__args...));
4380 return std::move(__sink)._M_finish();
4383#ifdef _GLIBCXX_USE_WCHAR_T
4384 template<typename _Out, typename... _Args>
4385 requires output_iterator<_Out, const wchar_t&>
4386 inline format_to_n_result<_Out>
4387 format_to_n(_Out __out, iter_difference_t<_Out> __n,
4388 wformat_string<_Args...> __fmt, _Args&&... __args)
4390 __format::_Iter_sink<wchar_t, _Out> __sink(std::move(__out), __n);
4391 std::vformat_to(__sink.out(), __fmt.get(),
4392 std::make_wformat_args(__args...));
4393 return std::move(__sink)._M_finish();
4397 template<typename _Out, typename... _Args>
4398 requires output_iterator<_Out, const char&>
4399 inline format_to_n_result<_Out>
4400 format_to_n(_Out __out, iter_difference_t<_Out> __n, const locale& __loc,
4401 format_string<_Args...> __fmt, _Args&&... __args)
4403 __format::_Iter_sink<char, _Out> __sink(std::move(__out), __n);
4404 std::vformat_to(__sink.out(), __loc, __fmt.get(),
4405 std::make_format_args(__args...));
4406 return std::move(__sink)._M_finish();
4409#ifdef _GLIBCXX_USE_WCHAR_T
4410 template<typename _Out, typename... _Args>
4411 requires output_iterator<_Out, const wchar_t&>
4412 inline format_to_n_result<_Out>
4413 format_to_n(_Out __out, iter_difference_t<_Out> __n, const locale& __loc,
4414 wformat_string<_Args...> __fmt, _Args&&... __args)
4416 __format::_Iter_sink<wchar_t, _Out> __sink(std::move(__out), __n);
4417 std::vformat_to(__sink.out(), __loc, __fmt.get(),
4418 std::make_wformat_args(__args...));
4419 return std::move(__sink)._M_finish();
4423/// @cond undocumented
4427 template<typename _CharT>
4428 class _Counting_sink final : public _Iter_sink<_CharT, _CharT*>
4431 _Counting_sink() : _Iter_sink<_CharT, _CharT*>(nullptr, 0) { }
4433 [[__gnu__::__always_inline__]]
4436 { return this->_M_count + this->_M_used().size(); }
4439 template<typename _CharT>
4440 class _Counting_sink : public _Buf_sink<_CharT>
4442 size_t _M_count = 0;
4445 _M_overflow() override
4447 if (!std::is_constant_evaluated())
4448 _M_count += this->_M_used().size();
4453 _Counting_sink() = default;
4455 [[__gnu__::__always_inline__]]
4459 _Counting_sink::_M_overflow();
4464} // namespace __format
4467 template<typename... _Args>
4470 formatted_size(format_string<_Args...> __fmt, _Args&&... __args)
4472 __format::_Counting_sink<char> __buf;
4473 std::vformat_to(__buf.out(), __fmt.get(),
4474 std::make_format_args(__args...));
4475 return __buf.count();
4478#ifdef _GLIBCXX_USE_WCHAR_T
4479 template<typename... _Args>
4482 formatted_size(wformat_string<_Args...> __fmt, _Args&&... __args)
4484 __format::_Counting_sink<wchar_t> __buf;
4485 std::vformat_to(__buf.out(), __fmt.get(),
4486 std::make_wformat_args(__args...));
4487 return __buf.count();
4491 template<typename... _Args>
4494 formatted_size(const locale& __loc, format_string<_Args...> __fmt,
4497 __format::_Counting_sink<char> __buf;
4498 std::vformat_to(__buf.out(), __loc, __fmt.get(),
4499 std::make_format_args(__args...));
4500 return __buf.count();
4503#ifdef _GLIBCXX_USE_WCHAR_T
4504 template<typename... _Args>
4507 formatted_size(const locale& __loc, wformat_string<_Args...> __fmt,
4510 __format::_Counting_sink<wchar_t> __buf;
4511 std::vformat_to(__buf.out(), __loc, __fmt.get(),
4512 std::make_wformat_args(__args...));
4513 return __buf.count();
4517#if __cpp_lib_format_ranges
4518 // [format.range], formatting of ranges
4519 // [format.range.fmtkind], variable template format_kind
4520 enum class range_format {
4529 /// @cond undocumented
4530 template<typename _Rg>
4531 constexpr auto format_kind = not defined(format_kind<_Rg>);
4533 template<typename _Tp>
4534 consteval range_format
4537 using _Ref = ranges::range_reference_t<_Tp>;
4538 if constexpr (is_same_v<remove_cvref_t<_Ref>, _Tp>)
4539 return range_format::disabled;
4540 else if constexpr (requires { typename _Tp::key_type; })
4542 if constexpr (requires { typename _Tp::mapped_type; })
4544 using _Up = remove_cvref_t<_Ref>;
4545 if constexpr (__is_pair<_Up>)
4546 return range_format::map;
4547 else if constexpr (__is_specialization_of<_Up, tuple>)
4548 if constexpr (tuple_size_v<_Up> == 2)
4549 return range_format::map;
4551 return range_format::set;
4554 return range_format::sequence;
4558 /// A constant determining how a range should be formatted.
4559 template<ranges::input_range _Rg> requires same_as<_Rg, remove_cvref_t<_Rg>>
4560 constexpr range_format format_kind<_Rg> = __fmt_kind<_Rg>();
4562 // [format.range.formatter], class template range_formatter
4563 template<typename _Tp, typename _CharT = char>
4564 requires same_as<remove_cvref_t<_Tp>, _Tp> && formattable<_Tp, _CharT>
4565 class range_formatter; // TODO
4567/// @cond undocumented
4570 // [format.range.fmtdef], class template range-default-formatter
4571 template<range_format _Kind, ranges::input_range _Rg, typename _CharT>
4572 struct __range_default_formatter; // TODO
4573} // namespace __format
4576 // [format.range.fmtmap], [format.range.fmtset], [format.range.fmtstr],
4577 // specializations for maps, sets, and strings
4578 template<ranges::input_range _Rg, typename _CharT>
4579 requires (format_kind<_Rg> != range_format::disabled)
4580 && formattable<ranges::range_reference_t<_Rg>, _CharT>
4581 struct formatter<_Rg, _CharT>
4582 : __format::__range_default_formatter<format_kind<_Rg>, _Rg, _CharT>
4584#endif // C++23 formatting ranges
4586_GLIBCXX_END_NAMESPACE_VERSION
4588#endif // __cpp_lib_format
4589#endif // _GLIBCXX_FORMAT