libstdc++: string_conversions.h Source File

libstdc++

string_conversions.h
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1// String Conversions -*- C++ -*-
2
3// Copyright (C) 2008-2026 Free Software Foundation, Inc.
4//
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)
9// any later version.
10
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.
15
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.
19
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/>.
24
25/** @file ext/string_conversions.h
26 * This file is a GNU extension to the Standard C++ Library.
27 */
28
29#ifndef _STRING_CONVERSIONS_H
30#define _STRING_CONVERSIONS_H 1
31
32#ifdef _GLIBCXX_SYSHDR
33#pragma GCC system_header
34#endif
35
36#include <bits/requires_hosted.h> // GNU extensions are currently omitted
37
38#if __cplusplus < 201103L
39# include <bits/c++0x_warning.h>
40#else
41
42#include <bits/c++config.h>
43#include <ext/numeric_traits.h>
44#include <bits/stdexcept_throw.h>
45#include <cstdlib>
46#include <cwchar>
47#include <cstdio>
48#include <cerrno>
49
50namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
51{
52_GLIBCXX_BEGIN_NAMESPACE_VERSION
53
54 // Helper for all the sto* functions.
55 template<typename _TRet, typename _Ret = _TRet, typename _CharT,
56 typename... _Base>
57 _Ret
58 __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
59 const char* __name, const _CharT* __str, std::size_t* __idx,
60 _Base... __base)
61 {
62 _Ret __ret;
63
64 _CharT* __endptr;
65
66 struct _Save_errno {
67 _Save_errno() : _M_errno(errno) { errno = 0; }
68 ~_Save_errno() { if (errno == 0) errno = _M_errno; }
69 int _M_errno;
70 } const __save_errno;
71
72 struct _Range_chk {
73 static bool
74 _S_chk(_TRet, std::false_type) { return false; }
75
76 static bool
77 _S_chk(_TRet __val, std::true_type) // only called when _Ret is int
78 {
79 return __val < _TRet(__numeric_traits<int>::__min)
80 || __val > _TRet(__numeric_traits<int>::__max);
81 }
82 };
83
84 const _TRet __tmp = __convf(__str, &__endptr, __base...);
85
86 if (__endptr == __str)
87 std::__throw_invalid_argument(__name);
88 else if (errno == ERANGE
89 || _Range_chk::_S_chk(__tmp, std::is_same<_Ret, int>{}))
90 std::__throw_out_of_range(__name);
91 else
92 __ret = __tmp;
93
94 if (__idx)
95 *__idx = __endptr - __str;
96
97 return __ret;
98 }
99
100 // Helper for the to_string / to_wstring functions.
101 template<typename _String, typename _CharT = typename _String::value_type>
102 _String
103 __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
104 __builtin_va_list), std::size_t __n,
105 const _CharT* __fmt, ...)
106 {
107 // XXX Eventually the result should be constructed in-place in
108 // the __cxx11 string, likely with the help of internal hooks.
109 _CharT* __s = static_cast<_CharT*>(__builtin_alloca(sizeof(_CharT)
110 * __n));
111
112 __builtin_va_list __args;
113 __builtin_va_start(__args, __fmt);
114
115 const int __len = __convf(__s, __n, __fmt, __args);
116
117 __builtin_va_end(__args);
118
119 return _String(__s, __s + __len);
120 }
121
122_GLIBCXX_END_NAMESPACE_VERSION
123} // namespace
124
125#endif // C++11
126
127#endif // _STRING_CONVERSIONS_H
cerrno
cstdio
cstdlib
cwchar
c++0x_warning.h
stdexcept_throw.h
requires_hosted.h
c++config.h
std::true_type
__bool_constant< true > true_type
The type used as a compile-time boolean with true value.
Definition type_traits:119
std::false_type
__bool_constant< false > false_type
The type used as a compile-time boolean with false value.
Definition type_traits:122
__gnu_cxx
GNU extensions for public use.
__gnu_debug::__base
constexpr _Iterator __base(_Iterator __it)
Definition helper_functions.h:339
numeric_traits.h