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The C and C++ Include Header Files
cat -n /usr/include/c++/15/iosfwd
1 // <iosfwd> Forward declarations -*- C++ -*- 2 3 // Copyright (C) 1997-2025 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 include/iosfwd 26 * This is a Standard C++ Library header. 27 */ 28 29 // 30 // ISO C++ 14882: 27.2 Forward declarations 31 // 32 33 #ifndef _GLIBCXX_IOSFWD 34 #define _GLIBCXX_IOSFWD 1 35 36 #ifdef _GLIBCXX_SYSHDR 37 #pragma GCC system_header 38 #endif 39 40 #include <bits/requires_hosted.h> // iostreams 41 42 #include <bits/c++config.h> 43 #include <bits/stringfwd.h> // For string forward declarations. 44 #include <bits/postypes.h> 45 46 namespace std _GLIBCXX_VISIBILITY(default) 47 { 48 _GLIBCXX_BEGIN_NAMESPACE_VERSION 49 50 /** 51 * @defgroup io I/O 52 * 53 * Nearly all of the I/O classes are parameterized on the type of 54 * characters they read and write. (The major exception is ios_base at 55 * the top of the hierarchy.) This is a change from pre-Standard 56 * streams, which were not templates. 57 * 58 * For ease of use and compatibility, all of the basic_* I/O-related 59 * classes are given typedef names for both of the builtin character 60 * widths (wide and narrow). The typedefs are the same as the 61 * pre-Standard names, for example: 62 * 63 * @code 64 * typedef basic_ifstream<char> ifstream; 65 * @endcode 66 * 67 * Because properly forward-declaring these classes can be difficult, you 68 * should not do it yourself. Instead, include the <iosfwd> 69 * header, which contains only declarations of all the I/O classes as 70 * well as the typedefs. Trying to forward-declare the typedefs 71 * themselves (e.g., <code>class ostream;</code>) is not valid ISO C++. 72 * 73 * For more specific declarations, see 74 * https://gcc.gnu.org/onlinedocs/libstdc++/manual/io.html#std.io.objects 75 * 76 * @{ 77 */ 78 class ios_base; 79 80 template<typename _CharT, typename _Traits = char_traits<_CharT> > 81 class basic_ios; 82 83 template<typename _CharT, typename _Traits = char_traits<_CharT> > 84 class basic_streambuf; 85 86 template<typename _CharT, typename _Traits = char_traits<_CharT> > 87 class basic_istream; 88 89 template<typename _CharT, typename _Traits = char_traits<_CharT> > 90 class basic_ostream; 91 92 template<typename _CharT, typename _Traits = char_traits<_CharT> > 93 class basic_iostream; 94 95 96 _GLIBCXX_BEGIN_NAMESPACE_CXX11 97 98 template<typename _CharT, typename _Traits = char_traits<_CharT>, 99 typename _Alloc = allocator<_CharT> > 100 class basic_stringbuf; 101 102 template<typename _CharT, typename _Traits = char_traits<_CharT>, 103 typename _Alloc = allocator<_CharT> > 104 class basic_istringstream; 105 106 template<typename _CharT, typename _Traits = char_traits<_CharT>, 107 typename _Alloc = allocator<_CharT> > 108 class basic_ostringstream; 109 110 template<typename _CharT, typename _Traits = char_traits<_CharT>, 111 typename _Alloc = allocator<_CharT> > 112 class basic_stringstream; 113 114 _GLIBCXX_END_NAMESPACE_CXX11 115 116 template<typename _CharT, typename _Traits = char_traits<_CharT> > 117 class basic_filebuf; 118 119 template<typename _CharT, typename _Traits = char_traits<_CharT> > 120 class basic_ifstream; 121 122 template<typename _CharT, typename _Traits = char_traits<_CharT> > 123 class basic_ofstream; 124 125 template<typename _CharT, typename _Traits = char_traits<_CharT> > 126 class basic_fstream; 127 128 template<typename _CharT, typename _Traits = char_traits<_CharT> > 129 class istreambuf_iterator; 130 131 template<typename _CharT, typename _Traits = char_traits<_CharT> > 132 class ostreambuf_iterator; 133 134 135 /// Base class for @c char streams. 136 typedef basic_ios<char> ios; 137 138 /// Base class for @c char buffers. 139 typedef basic_streambuf<char> streambuf; 140 141 /// Base class for @c char input streams. 142 typedef basic_istream<char> istream; 143 144 /// Base class for @c char output streams. 145 typedef basic_ostream<char> ostream; 146 147 /// Base class for @c char mixed input and output streams. 148 typedef basic_iostream<char> iostream; 149 150 /// Class for @c char memory buffers. 151 typedef basic_stringbuf<char> stringbuf; 152 153 /// Class for @c char input memory streams. 154 typedef basic_istringstream<char> istringstream; 155 156 /// Class for @c char output memory streams. 157 typedef basic_ostringstream<char> ostringstream; 158 159 /// Class for @c char mixed input and output memory streams. 160 typedef basic_stringstream<char> stringstream; 161 162 /// Class for @c char file buffers. 163 typedef basic_filebuf<char> filebuf; 164 165 /// Class for @c char input file streams. 166 typedef basic_ifstream<char> ifstream; 167 168 /// Class for @c char output file streams. 169 typedef basic_ofstream<char> ofstream; 170 171 /// Class for @c char mixed input and output file streams. 172 typedef basic_fstream<char> fstream; 173 174 #ifdef _GLIBCXX_USE_WCHAR_T 175 /// Base class for @c wchar_t streams. 176 typedef basic_ios<wchar_t> wios; 177 178 /// Base class for @c wchar_t buffers. 179 typedef basic_streambuf<wchar_t> wstreambuf; 180 181 /// Base class for @c wchar_t input streams. 182 typedef basic_istream<wchar_t> wistream; 183 184 /// Base class for @c wchar_t output streams. 185 typedef basic_ostream<wchar_t> wostream; 186 187 /// Base class for @c wchar_t mixed input and output streams. 188 typedef basic_iostream<wchar_t> wiostream; 189 190 /// Class for @c wchar_t memory buffers. 191 typedef basic_stringbuf<wchar_t> wstringbuf; 192 193 /// Class for @c wchar_t input memory streams. 194 typedef basic_istringstream<wchar_t> wistringstream; 195 196 /// Class for @c wchar_t output memory streams. 197 typedef basic_ostringstream<wchar_t> wostringstream; 198 199 /// Class for @c wchar_t mixed input and output memory streams. 200 typedef basic_stringstream<wchar_t> wstringstream; 201 202 /// Class for @c wchar_t file buffers. 203 typedef basic_filebuf<wchar_t> wfilebuf; 204 205 /// Class for @c wchar_t input file streams. 206 typedef basic_ifstream<wchar_t> wifstream; 207 208 /// Class for @c wchar_t output file streams. 209 typedef basic_ofstream<wchar_t> wofstream; 210 211 /// Class for @c wchar_t mixed input and output file streams. 212 typedef basic_fstream<wchar_t> wfstream; 213 #endif 214 215 #if __cplusplus >= 202002L && _GLIBCXX_USE_CXX11_ABI 216 template<typename _CharT, typename _Traits = char_traits<_CharT>, 217 typename _Allocator = allocator<_CharT>> 218 class basic_syncbuf; 219 template<typename _CharT, typename _Traits = char_traits<_CharT>, 220 typename _Allocator = allocator<_CharT>> 221 class basic_osyncstream; 222 223 using syncbuf = basic_syncbuf<char>; 224 using osyncstream = basic_osyncstream<char>; 225 226 #ifdef _GLIBCXX_USE_WCHAR_T 227 using wsyncbuf = basic_syncbuf<wchar_t>; 228 using wosyncstream = basic_osyncstream<wchar_t>; 229 #endif 230 #endif // C++20 && CXX11_ABI 231 232 #if __cplusplus > 202002L 233 template<typename _CharT, typename _Traits = char_traits<_CharT>> 234 class basic_spanbuf; 235 template<typename _CharT, typename _Traits = char_traits<_CharT>> 236 class basic_ispanstream; 237 template<typename _CharT, typename _Traits = char_traits<_CharT>> 238 class basic_ospanstream; 239 template<typename _CharT, typename _Traits = char_traits<_CharT>> 240 class basic_spanstream; 241 242 using spanbuf = basic_spanbuf<char>; 243 using ispanstream = basic_ispanstream<char>; 244 using ospanstream = basic_ospanstream<char>; 245 using spanstream = basic_spanstream<char>; 246 247 #ifdef _GLIBCXX_USE_WCHAR_T 248 using wspanbuf = basic_spanbuf<wchar_t>; 249 using wispanstream = basic_ispanstream<wchar_t>; 250 using wospanstream = basic_ospanstream<wchar_t>; 251 using wspanstream = basic_spanstream<wchar_t>; 252 #endif 253 #endif // C++23 254 255 /** @} */ 256 257 _GLIBCXX_END_NAMESPACE_VERSION 258 } // namespace 259 260 #endif /* _GLIBCXX_IOSFWD */
