libstdc++
string_conversions.h
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1// String Conversions -*- C++ -*-
2
3// Copyright (C) 2008-2022 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#pragma GCC system_header
33
34#include <bits/requires_hosted.h> // GNU extensions are currently omitted
35
36#if __cplusplus < 201103L
37# include <bits/c++0x_warning.h>
38#else
39
40#include <bits/c++config.h>
41#include <ext/numeric_traits.h>
42#include <bits/functexcept.h>
43#include <cstdlib>
44#include <cwchar>
45#include <cstdio>
46#include <cerrno>
47
48namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
49{
50_GLIBCXX_BEGIN_NAMESPACE_VERSION
51
52 // Helper for all the sto* functions.
53 template<typename _TRet, typename _Ret = _TRet, typename _CharT,
54 typename... _Base>
55 _Ret
56 __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
57 const char* __name, const _CharT* __str, std::size_t* __idx,
58 _Base... __base)
59 {
60 _Ret __ret;
61
62 _CharT* __endptr;
63
64 struct _Save_errno {
65 _Save_errno() : _M_errno(errno) { errno = 0; }
66 ~_Save_errno() { if (errno == 0) errno = _M_errno; }
67 int _M_errno;
68 } const __save_errno;
69
70 struct _Range_chk {
71 static bool
72 _S_chk(_TRet, std::false_type) { return false; }
73
74 static bool
75 _S_chk(_TRet __val, std::true_type) // only called when _Ret is int
76 {
77 return __val < _TRet(__numeric_traits<int>::__min)
78 || __val > _TRet(__numeric_traits<int>::__max);
79 }
80 };
81
82 const _TRet __tmp = __convf(__str, &__endptr, __base...);
83
84 if (__endptr == __str)
85 std::__throw_invalid_argument(__name);
86 else if (errno == ERANGE
87 || _Range_chk::_S_chk(__tmp, std::is_same<_Ret, int>{}))
88 std::__throw_out_of_range(__name);
89 else
90 __ret = __tmp;
91
92 if (__idx)
93 *__idx = __endptr - __str;
94
95 return __ret;
96 }
97
98 // Helper for the to_string / to_wstring functions.
99 template<typename _String, typename _CharT = typename _String::value_type>
100 _String
101 __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
102 __builtin_va_list), std::size_t __n,
103 const _CharT* __fmt, ...)
104 {
105 // XXX Eventually the result should be constructed in-place in
106 // the __cxx11 string, likely with the help of internal hooks.
107 _CharT* __s = static_cast<_CharT*>(__builtin_alloca(sizeof(_CharT)
108 * __n));
109
110 __builtin_va_list __args;
111 __builtin_va_start(__args, __fmt);
112
113 const int __len = __convf(__s, __n, __fmt, __args);
114
115 __builtin_va_end(__args);
116
117 return _String(__s, __s + __len);
118 }
119
120_GLIBCXX_END_NAMESPACE_VERSION
121} // namespace
122
123#endif // C++11
124
125#endif // _STRING_CONVERSIONS_H
GNU extensions for public use.
constexpr _Iterator __base(_Iterator __it)
integral_constant
Definition: type_traits:63
is_same
Definition: type_traits:1369