libstdc++
string_conversions.h
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00001 // String Conversions -*- C++ -*-
00002 
00003 // Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc.
00004 //
00005 // This file is part of the GNU ISO C++ Library.  This library is free
00006 // software; you can redistribute it and/or modify it under the
00007 // terms of the GNU General Public License as published by the
00008 // Free Software Foundation; either version 3, or (at your option)
00009 // any later version.
00010 
00011 // This library is distributed in the hope that it will be useful,
00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014 // GNU General Public License for more details.
00015 
00016 // Under Section 7 of GPL version 3, you are granted additional
00017 // permissions described in the GCC Runtime Library Exception, version
00018 // 3.1, as published by the Free Software Foundation.
00019 
00020 // You should have received a copy of the GNU General Public License and
00021 // a copy of the GCC Runtime Library Exception along with this program;
00022 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
00023 // <http://www.gnu.org/licenses/>.
00024 
00025 /** @file ext/string_conversions.h
00026  *  This file is a GNU extension to the Standard C++ Library.
00027  */
00028 
00029 #ifndef _STRING_CONVERSIONS_H
00030 #define _STRING_CONVERSIONS_H 1
00031 
00032 #pragma GCC system_header
00033 
00034 #include <bits/c++config.h>
00035 #include <ext/numeric_traits.h>
00036 #include <bits/functexcept.h>
00037 #include <cstdlib>
00038 #include <cwchar>
00039 #include <cstdio>
00040 #include <cerrno>
00041 
00042 namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
00043 {
00044 _GLIBCXX_BEGIN_NAMESPACE_VERSION
00045 
00046   // Helper for all the sto* functions.
00047   template<typename _TRet, typename _Ret = _TRet, typename _CharT,
00048        typename... _Base>
00049     _Ret
00050     __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
00051        const char* __name, const _CharT* __str, std::size_t* __idx,
00052        _Base... __base)
00053     {
00054       _Ret __ret;
00055 
00056       _CharT* __endptr;
00057       errno = 0;
00058       const _TRet __tmp = __convf(__str, &__endptr, __base...);
00059 
00060       if (__endptr == __str)
00061     std::__throw_invalid_argument(__name);
00062       else if (errno == ERANGE
00063            || (std::__are_same<_Ret, int>::__value
00064            && (__tmp < __numeric_traits<int>::__min
00065                || __tmp > __numeric_traits<int>::__max)))
00066     std::__throw_out_of_range(__name);
00067       else
00068     __ret = __tmp;
00069 
00070       if (__idx)
00071     *__idx = __endptr - __str;
00072 
00073       return __ret;
00074     }
00075 
00076   // Helper for the to_string / to_wstring functions.
00077   template<typename _String, typename _CharT = typename _String::value_type>
00078     _String
00079     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
00080                  __builtin_va_list), std::size_t __n,
00081          const _CharT* __fmt, ...)
00082     {
00083       // XXX Eventually the result will be constructed in place in
00084       // the C++0x string, likely with the help of internal hooks.
00085       _CharT* __s = static_cast<_CharT*>(__builtin_alloca(sizeof(_CharT)
00086                               * __n));
00087 
00088       __builtin_va_list __args;
00089       __builtin_va_start(__args, __fmt);
00090 
00091       const int __len = __convf(__s, __n, __fmt, __args);
00092 
00093       __builtin_va_end(__args);
00094 
00095       return _String(__s, __s + __len);
00096     }
00097 
00098 _GLIBCXX_END_NAMESPACE_VERSION
00099 } // namespace
00100 
00101 #endif // _STRING_CONVERSIONS_H