libstdc++-v3/include/ext/string_conversions.h

   1 // String Conversions -*- C++ -*-
   2
   3 // Copyright (C) 2008, 2009, 2010 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 #ifndef _STRING_CONVERSIONS_H
  26 #define _STRING_CONVERSIONS_H 1
  27
  28 #pragma GCC system_header
  29
  30 #include <bits/c++config.h>
  31 #include <ext/numeric_traits.h>
  32 #include <bits/functexcept.h>
  33 #include <cstdlib>
  34 #include <cwchar>
  35 #include <cstdio>
  36 #include <cerrno>
  37
  38 _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
  39
  40   // Helper for all the sto* functions.
  41   template<typename _TRet, typename _Ret = _TRet, typename _CharT,
  42            typename... _Base>
  43     _Ret
  44     __stoa(_TRet (*__convf) (const _CharT*, _CharT**, _Base...),
  45            const char* __name, const _CharT* __str, std::size_t* __idx,
  46            _Base... __base)
  47     {
  48       _Ret __ret;
  49
  50       _CharT* __endptr;
  51       errno = 0;
  52       const _TRet __tmp = __convf(__str, &__endptr, __base...);
  53
  54       if (__endptr == __str)
  55         std::__throw_invalid_argument(__name);
  56       else if (errno == ERANGE
  57                || (std::__are_same<_Ret, int>::__value
  58                    && (__tmp < __numeric_traits<int>::__min
  59                        || __tmp > __numeric_traits<int>::__max)))
  60         std::__throw_out_of_range(__name);
  61       else
  62         __ret = __tmp;
  63
  64       if (__idx)
  65         *__idx = __endptr - __str;
  66
  67       return __ret;
  68     }
  69
  70   // Helper for the to_string / to_wstring functions.
  71   template<typename _String, typename _CharT = typename _String::value_type>
  72     _String
  73     __to_xstring(int (*__convf) (_CharT*, std::size_t, const _CharT*,
  74                                  __builtin_va_list), std::size_t __n,
  75                  const _CharT* __fmt, ...)
  76     {
  77       // XXX Eventually the result will be constructed in place in
  78       // the C++0x string, likely with the help of internal hooks.
  79       _CharT* __s = static_cast<_CharT*>(__builtin_alloca(sizeof(_CharT)
  80                                                           * __n));
  81
  82       __builtin_va_list __args;
  83       __builtin_va_start(__args, __fmt);
  84
  85       const int __len = __convf(__s, __n, __fmt, __args);
  86
  87       __builtin_va_end(__args);
  88
  89       return _String(__s, __s + __len);
  90     }
  91
  92 _GLIBCXX_END_NAMESPACE
  93
  94 #endif // _STRING_CONVERSIONS_H