1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
|
// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#ifndef _LIBCPP___FORMAT_FORMATTER_TUPLE_H
#define _LIBCPP___FORMAT_FORMATTER_TUPLE_H
#include <__algorithm/ranges_copy.h>
#include <__availability>
#include <__chrono/statically_widen.h>
#include <__config>
#include <__format/buffer.h>
#include <__format/concepts.h>
#include <__format/format_args.h>
#include <__format/format_context.h>
#include <__format/format_error.h>
#include <__format/format_parse_context.h>
#include <__format/formatter.h>
#include <__format/formatter_output.h>
#include <__format/parser_std_format_spec.h>
#include <__iterator/back_insert_iterator.h>
#include <__type_traits/remove_cvref.h>
#include <__utility/integer_sequence.h>
#include <__utility/pair.h>
#include <string_view>
#include <tuple>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER >= 23
template <__fmt_char_type _CharT, class _Tuple, formattable<_CharT>... _Args>
struct _LIBCPP_TEMPLATE_VIS __formatter_tuple {
_LIBCPP_HIDE_FROM_ABI constexpr void set_separator(basic_string_view<_CharT> __separator) noexcept {
__separator_ = __separator;
}
_LIBCPP_HIDE_FROM_ABI constexpr void
set_brackets(basic_string_view<_CharT> __opening_bracket, basic_string_view<_CharT> __closing_bracket) noexcept {
__opening_bracket_ = __opening_bracket;
__closing_bracket_ = __closing_bracket;
}
template <class _ParseContext>
_LIBCPP_HIDE_FROM_ABI constexpr typename _ParseContext::iterator parse(_ParseContext& __ctx) {
auto __begin = __parser_.__parse(__ctx, __format_spec::__fields_tuple);
auto __end = __ctx.end();
if (__begin != __end) {
if (*__begin == _CharT('m')) {
if constexpr (sizeof...(_Args) == 2) {
set_separator(_LIBCPP_STATICALLY_WIDEN(_CharT, ": "));
set_brackets({}, {});
++__begin;
} else
std::__throw_format_error("The format specifier m requires a pair or a two-element tuple");
} else if (*__begin == _CharT('n')) {
set_brackets({}, {});
++__begin;
}
}
if (__begin != __end && *__begin != _CharT('}'))
std::__throw_format_error("The format-spec should consume the input or end with a '}'");
__ctx.advance_to(__begin);
// [format.tuple]/7
// ... For each element e in underlying_, if e.set_debug_format()
// is a valid expression, calls e.set_debug_format().
std::__for_each_index_sequence(make_index_sequence<sizeof...(_Args)>(), [&]<size_t _Index> {
auto& __formatter = std::get<_Index>(__underlying_);
__formatter.parse(__ctx);
// Unlike the range_formatter we don't guard against evil parsers. Since
// this format-spec never has a format-spec for the underlying type
// adding the test would give additional overhead.
std::__set_debug_format(__formatter);
});
return __begin;
}
template <class _FormatContext>
typename _FormatContext::iterator _LIBCPP_HIDE_FROM_ABI
format(conditional_t<(formattable<const _Args, _CharT> && ...), const _Tuple&, _Tuple&> __tuple,
_FormatContext& __ctx) const {
__format_spec::__parsed_specifications<_CharT> __specs = __parser_.__get_parsed_std_specifications(__ctx);
if (!__specs.__has_width())
return __format_tuple(__tuple, __ctx);
// The size of the buffer needed is:
// - open bracket characters
// - close bracket character
// - n elements where every element may have a different size
// - (n -1) separators
// The size of the element is hard to predict, knowing the type helps but
// it depends on the format-spec. As an initial estimate we guess 6
// characters.
// Typically both brackets are 1 character and the separator is 2
// characters. Which means there will be
// (n - 1) * 2 + 1 + 1 = n * 2 character
// So estimate 8 times the range size as buffer.
__format::__retarget_buffer<_CharT> __buffer{8 * tuple_size_v<_Tuple>};
basic_format_context<typename __format::__retarget_buffer<_CharT>::__iterator, _CharT> __c{
__buffer.__make_output_iterator(), __ctx};
__format_tuple(__tuple, __c);
return __formatter::__write_string_no_precision(basic_string_view{__buffer.__view()}, __ctx.out(), __specs);
}
template <class _FormatContext>
_LIBCPP_HIDE_FROM_ABI typename _FormatContext::iterator __format_tuple(auto&& __tuple, _FormatContext& __ctx) const {
__ctx.advance_to(std::ranges::copy(__opening_bracket_, __ctx.out()).out);
std::__for_each_index_sequence(make_index_sequence<sizeof...(_Args)>(), [&]<size_t _Index> {
if constexpr (_Index)
__ctx.advance_to(std::ranges::copy(__separator_, __ctx.out()).out);
__ctx.advance_to(std::get<_Index>(__underlying_).format(std::get<_Index>(__tuple), __ctx));
});
return std::ranges::copy(__closing_bracket_, __ctx.out()).out;
}
__format_spec::__parser<_CharT> __parser_{.__alignment_ = __format_spec::__alignment::__left};
private:
tuple<formatter<remove_cvref_t<_Args>, _CharT>...> __underlying_;
basic_string_view<_CharT> __separator_ = _LIBCPP_STATICALLY_WIDEN(_CharT, ", ");
basic_string_view<_CharT> __opening_bracket_ = _LIBCPP_STATICALLY_WIDEN(_CharT, "(");
basic_string_view<_CharT> __closing_bracket_ = _LIBCPP_STATICALLY_WIDEN(_CharT, ")");
};
template <__fmt_char_type _CharT, formattable<_CharT>... _Args>
struct _LIBCPP_TEMPLATE_VIS formatter<pair<_Args...>, _CharT>
: public __formatter_tuple<_CharT, pair<_Args...>, _Args...> {};
template <__fmt_char_type _CharT, formattable<_CharT>... _Args>
struct _LIBCPP_TEMPLATE_VIS formatter<tuple<_Args...>, _CharT>
: public __formatter_tuple<_CharT, tuple<_Args...>, _Args...> {};
#endif //_LIBCPP_STD_VER >= 23
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___FORMAT_FORMATTER_TUPLE_H
|
