libstdc++-v3/include/bits/ostream_insert.h

   1 // Helpers for ostream inserters -*- C++ -*-
   2
   3 // Copyright (C) 2007 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 2, 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 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  19 // USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 /** @file ostream_insert.h
  31  *  This is an internal header file, included by other library headers.
  32  *  You should not attempt to use it directly.
  33  */
  34
  35 #ifndef _OSTREAM_INSERT_H
  36 #define _OSTREAM_INSERT_H 1
  37
  38 #pragma GCC system_header
  39
  40 #include <iosfwd>
  41 #include <cxxabi-internal.h>
  42
  43 _GLIBCXX_BEGIN_NAMESPACE(std)
  44
  45   template<typename _CharT, typename _Traits>
  46     inline void
  47     __ostream_write(basic_ostream<_CharT, _Traits>& __out,
  48                     const _CharT* __s, streamsize __n)
  49     {
  50       typedef basic_ostream<_CharT, _Traits>       __ostream_type;
  51       typedef typename __ostream_type::ios_base    __ios_base;
  52
  53       const streamsize __put = __out.rdbuf()->sputn(__s, __n);
  54       if (__put != __n)
  55         __out.setstate(__ios_base::badbit);
  56     }
  57
  58   template<typename _CharT, typename _Traits>
  59     inline void
  60     __ostream_fill(basic_ostream<_CharT, _Traits>& __out, streamsize __n)
  61     {
  62       typedef basic_ostream<_CharT, _Traits>       __ostream_type;
  63       typedef typename __ostream_type::ios_base    __ios_base;
  64
  65       const _CharT __c = __out.fill();
  66       for (; __n > 0; --__n)
  67         {
  68           const typename _Traits::int_type __put = __out.rdbuf()->sputc(__c);
  69           if (_Traits::eq_int_type(__put, _Traits::eof()))
  70             {
  71               __out.setstate(__ios_base::badbit);
  72               break;
  73             }
  74         }
  75     }
  76
  77   template<typename _CharT, typename _Traits>
  78     basic_ostream<_CharT, _Traits>&
  79     __ostream_insert(basic_ostream<_CharT, _Traits>& __out,
  80                      const _CharT* __s, streamsize __n)
  81     {
  82       typedef basic_ostream<_CharT, _Traits>       __ostream_type;
  83       typedef typename __ostream_type::ios_base    __ios_base;
  84
  85       typename __ostream_type::sentry __cerb(__out);
  86       if (__cerb)
  87         {
  88           try
  89             {
  90               const streamsize __w = __out.width();
  91               if (__w > __n)
  92                 {
  93                   const bool __left = ((__out.flags()
  94                                         & __ios_base::adjustfield)
  95                                        == __ios_base::left);
  96                   if (!__left)
  97                     __ostream_fill(__out, __w - __n);
  98                   if (__out.good())
  99                     __ostream_write(__out, __s, __n);
 100                   if (__left && __out.good())
 101                     __ostream_fill(__out, __w - __n);
 102                 }
 103               else
 104                 __ostream_write(__out, __s, __n);
 105               __out.width(0);
 106             }
 107           catch(__cxxabiv1::__forced_unwind&)
 108             {
 109               __out._M_setstate(__ios_base::badbit);
 110               __throw_exception_again;
 111             }
 112           catch(...)
 113             { __out._M_setstate(__ios_base::badbit); }
 114         }
 115       return __out;
 116     }
 117
 118   // Inhibit implicit instantiations for required instantiations,
 119   // which are defined via explicit instantiations elsewhere.
 120   // NB:  This syntax is a GNU extension.
 121 #if _GLIBCXX_EXTERN_TEMPLATE
 122   extern template ostream& __ostream_insert(ostream&, const char*, streamsize);
 123
 124 #ifdef _GLIBCXX_USE_WCHAR_T
 125   extern template wostream& __ostream_insert(wostream&, const wchar_t*,
 126                                              streamsize);
 127 #endif
 128 #endif
 129
 130 _GLIBCXX_END_NAMESPACE
 131
 132 #endif /* _OSTREAM_INSERT_H */