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

   1 // Helpers for ostream inserters -*- C++ -*-
   2
   3 // Copyright (C) 2007-2025 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 bits/ostream_insert.h
  26  *  This is an internal header file, included by other library headers.
  27  *  Do not attempt to use it directly. @headername{ostream}
  28  */
  29
  30 #ifndef _OSTREAM_INSERT_H
  31 #define _OSTREAM_INSERT_H 1
  32
  33 #ifdef _GLIBCXX_SYSHDR
  34 #pragma GCC system_header
  35 #endif
  36
  37 #include <iosfwd>
  38 #include <bits/cxxabi_forced.h>
  39 #include <bits/exception_defines.h>
  40
  41 #pragma GCC diagnostic push
  42 #pragma GCC diagnostic ignored "-Wc++11-extensions" // extern template
  43
  44 namespace std _GLIBCXX_VISIBILITY(default)
  45 {
  46 _GLIBCXX_BEGIN_NAMESPACE_VERSION
  47
  48   /// @cond undocumented
  49
  50   template<typename _CharT, typename _Traits>
  51     inline void
  52     __ostream_write(basic_ostream<_CharT, _Traits>& __out,
  53                     const _CharT* __s, streamsize __n)
  54     {
  55       typedef basic_ostream<_CharT, _Traits>       __ostream_type;
  56       typedef typename __ostream_type::ios_base    __ios_base;
  57
  58       const streamsize __put = __out.rdbuf()->sputn(__s, __n);
  59       if (__put != __n)
  60         __out.setstate(__ios_base::badbit);
  61     }
  62
  63   template<typename _CharT, typename _Traits>
  64     inline void
  65     __ostream_fill(basic_ostream<_CharT, _Traits>& __out, streamsize __n)
  66     {
  67       typedef basic_ostream<_CharT, _Traits>       __ostream_type;
  68       typedef typename __ostream_type::ios_base    __ios_base;
  69
  70       const _CharT __c = __out.fill();
  71       for (; __n > 0; --__n)
  72         {
  73           const typename _Traits::int_type __put = __out.rdbuf()->sputc(__c);
  74           if (_Traits::eq_int_type(__put, _Traits::eof()))
  75             {
  76               __out.setstate(__ios_base::badbit);
  77               break;
  78             }
  79         }
  80     }
  81
  82   template<typename _CharT, typename _Traits>
  83     basic_ostream<_CharT, _Traits>&
  84     __ostream_insert(basic_ostream<_CharT, _Traits>& __out,
  85                      const _CharT* __s, streamsize __n)
  86     {
  87       typedef basic_ostream<_CharT, _Traits>       __ostream_type;
  88       typedef typename __ostream_type::ios_base    __ios_base;
  89
  90       typename __ostream_type::sentry __cerb(__out);
  91       if (__cerb)
  92         {
  93           __try
  94             {
  95               const streamsize __w = __out.width();
  96               if (__w > __n)
  97                 {
  98                   const bool __left = ((__out.flags()
  99                                         & __ios_base::adjustfield)
 100                                        == __ios_base::left);
 101                   if (!__left)
 102                     __ostream_fill(__out, __w - __n);
 103                   if (__out.good())
 104                     __ostream_write(__out, __s, __n);
 105                   if (__left && __out.good())
 106                     __ostream_fill(__out, __w - __n);
 107                 }
 108               else
 109                 __ostream_write(__out, __s, __n);
 110               __out.width(0);
 111             }
 112           __catch(__cxxabiv1::__forced_unwind&)
 113             {
 114               __out._M_setstate(__ios_base::badbit);
 115               __throw_exception_again;
 116             }
 117           __catch(...)
 118             { __out._M_setstate(__ios_base::badbit); }
 119         }
 120       return __out;
 121     }
 122
 123   // Inhibit implicit instantiations for required instantiations,
 124   // which are defined via explicit instantiations elsewhere.
 125 #if _GLIBCXX_EXTERN_TEMPLATE
 126   extern template ostream& __ostream_insert(ostream&, const char*, streamsize);
 127
 128 #ifdef _GLIBCXX_USE_WCHAR_T
 129   extern template wostream& __ostream_insert(wostream&, const wchar_t*,
 130                                              streamsize);
 131 #endif
 132 #endif
 133
 134   /// @endcond
 135
 136 _GLIBCXX_END_NAMESPACE_VERSION
 137 } // namespace std
 138
 139 #pragma GCC diagnostic pop
 140 #endif /* _OSTREAM_INSERT_H */