1 // Streambuf iterators 2 3 // Copyright (C) 1997-2018 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/streambuf_iterator.h 26 * This is an internal header file, included by other library headers. 27 * Do not attempt to use it directly. @headername{iterator} 28 */ 29 30 #ifndef _STREAMBUF_ITERATOR_H 31 #define _STREAMBUF_ITERATOR_H 1 32 33 #pragma GCC system_header 34 35 #include <streambuf> 36 #include <debug/debug.h> 37 38 namespace std _GLIBCXX_VISIBILITY(default) 39 { 40 _GLIBCXX_BEGIN_NAMESPACE_VERSION 41 42 /** 43 * @addtogroup iterators 44 * @{ 45 */ 46 47 // 24.5.3 Template class istreambuf_iterator 48 /// Provides input iterator semantics for streambufs. 49 template<typename _CharT, typename _Traits> 50 class istreambuf_iterator 51 : public iterator<input_iterator_tag, _CharT, typename _Traits::off_type, 52 _CharT*, 53 #if __cplusplus >= 201103L 54 // LWG 445. 55 _CharT> 56 #else 57 _CharT&> 58 #endif 59 { 60 public: 61 // Types: 62 //@{ 63 /// Public typedefs 64 typedef _CharT char_type; 65 typedef _Traits traits_type; 66 typedef typename _Traits::int_type int_type; 67 typedef basic_streambuf<_CharT, _Traits> streambuf_type; 68 typedef basic_istream<_CharT, _Traits> istream_type; 69 //@} 70 71 template<typename _CharT2> 72 friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, 73 ostreambuf_iterator<_CharT2> >::__type 74 copy(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>, 75 ostreambuf_iterator<_CharT2>); 76 77 template<bool _IsMove, typename _CharT2> 78 friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, 79 _CharT2*>::__type 80 __copy_move_a2(istreambuf_iterator<_CharT2>, 81 istreambuf_iterator<_CharT2>, _CharT2*); 82 83 template<typename _CharT2> 84 friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, 85 istreambuf_iterator<_CharT2> >::__type 86 find(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>, 87 const _CharT2&); 88 89 template<typename _CharT2, typename _Distance> 90 friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, 91 void>::__type 92 advance(istreambuf_iterator<_CharT2>&, _Distance); 93 94 private: 95 // 24.5.3 istreambuf_iterator 96 // p 1 97 // If the end of stream is reached (streambuf_type::sgetc() 98 // returns traits_type::eof()), the iterator becomes equal to 99 // the "end of stream" iterator value. 100 // NB: This implementation assumes the "end of stream" value 101 // is EOF, or -1. 102 mutable streambuf_type* _M_sbuf; 103 int_type _M_c; 104 105 public: 106 /// Construct end of input stream iterator. 107 _GLIBCXX_CONSTEXPR istreambuf_iterator() _GLIBCXX_USE_NOEXCEPT 108 : _M_sbuf(0), _M_c(traits_type::eof()) { } 109 110 #if __cplusplus >= 201103L 111 istreambuf_iterator(const istreambuf_iterator&) noexcept = default; 112 113 ~istreambuf_iterator() = default; 114 #endif 115 116 /// Construct start of input stream iterator. 117 istreambuf_iterator(istream_type& __s) _GLIBCXX_USE_NOEXCEPT 118 : _M_sbuf(__s.rdbuf()), _M_c(traits_type::eof()) { } 119 120 /// Construct start of streambuf iterator. 121 istreambuf_iterator(streambuf_type* __s) _GLIBCXX_USE_NOEXCEPT 122 : _M_sbuf(__s), _M_c(traits_type::eof()) { } 123 124 /// Return the current character pointed to by iterator. This returns 125 /// streambuf.sgetc(). It cannot be assigned. NB: The result of 126 /// operator*() on an end of stream is undefined. 127 char_type 128 operator*() const 129 { 130 int_type __c = _M_get(); 131 132 #ifdef _GLIBCXX_DEBUG_PEDANTIC 133 // Dereferencing a past-the-end istreambuf_iterator is a 134 // libstdc++ extension 135 __glibcxx_requires_cond(!_S_is_eof(__c), 136 _M_message(__gnu_debug::__msg_deref_istreambuf) 137 ._M_iterator(*this)); 138 #endif 139 return traits_type::to_char_type(__c); 140 } 141 142 /// Advance the iterator. Calls streambuf.sbumpc(). 143 istreambuf_iterator& 144 operator++() 145 { 146 __glibcxx_requires_cond(_M_sbuf && 147 (!_S_is_eof(_M_c) || !_S_is_eof(_M_sbuf->sgetc())), 148 _M_message(__gnu_debug::__msg_inc_istreambuf) 149 ._M_iterator(*this)); 150 151 _M_sbuf->sbumpc(); 152 _M_c = traits_type::eof(); 153 return *this; 154 } 155 156 /// Advance the iterator. Calls streambuf.sbumpc(). 157 istreambuf_iterator 158 operator++(int) 159 { 160 __glibcxx_requires_cond(_M_sbuf && 161 (!_S_is_eof(_M_c) || !_S_is_eof(_M_sbuf->sgetc())), 162 _M_message(__gnu_debug::__msg_inc_istreambuf) 163 ._M_iterator(*this)); 164 165 istreambuf_iterator __old = *this; 166 __old._M_c = _M_sbuf->sbumpc(); 167 _M_c = traits_type::eof(); 168 return __old; 169 } 170 171 // _GLIBCXX_RESOLVE_LIB_DEFECTS 172 // 110 istreambuf_iterator::equal not const 173 // NB: there is also number 111 (NAD) relevant to this function. 174 /// Return true both iterators are end or both are not end. 175 bool 176 equal(const istreambuf_iterator& __b) const 177 { return _M_at_eof() == __b._M_at_eof(); } 178 179 private: 180 int_type 181 _M_get() const 182 { 183 int_type __ret = _M_c; 184 if (_M_sbuf && _S_is_eof(__ret) && _S_is_eof(__ret = _M_sbuf->sgetc())) 185 _M_sbuf = 0; 186 return __ret; 187 } 188 189 bool 190 _M_at_eof() const 191 { return _S_is_eof(_M_get()); } 192 193 static bool 194 _S_is_eof(int_type __c) 195 { 196 const int_type __eof = traits_type::eof(); 197 return traits_type::eq_int_type(__c, __eof); 198 } 199 }; 200 201 template<typename _CharT, typename _Traits> 202 inline bool 203 operator==(const istreambuf_iterator<_CharT, _Traits>& __a, 204 const istreambuf_iterator<_CharT, _Traits>& __b) 205 { return __a.equal(__b); } 206 207 template<typename _CharT, typename _Traits> 208 inline bool 209 operator!=(const istreambuf_iterator<_CharT, _Traits>& __a, 210 const istreambuf_iterator<_CharT, _Traits>& __b) 211 { return !__a.equal(__b); } 212 213 /// Provides output iterator semantics for streambufs. 214 template<typename _CharT, typename _Traits> 215 class ostreambuf_iterator 216 : public iterator<output_iterator_tag, void, void, void, void> 217 { 218 public: 219 // Types: 220 //@{ 221 /// Public typedefs 222 typedef _CharT char_type; 223 typedef _Traits traits_type; 224 typedef basic_streambuf<_CharT, _Traits> streambuf_type; 225 typedef basic_ostream<_CharT, _Traits> ostream_type; 226 //@} 227 228 template<typename _CharT2> 229 friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, 230 ostreambuf_iterator<_CharT2> >::__type 231 copy(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>, 232 ostreambuf_iterator<_CharT2>); 233 234 private: 235 streambuf_type* _M_sbuf; 236 bool _M_failed; 237 238 public: 239 /// Construct output iterator from ostream. 240 ostreambuf_iterator(ostream_type& __s) _GLIBCXX_USE_NOEXCEPT 241 : _M_sbuf(__s.rdbuf()), _M_failed(!_M_sbuf) { } 242 243 /// Construct output iterator from streambuf. 244 ostreambuf_iterator(streambuf_type* __s) _GLIBCXX_USE_NOEXCEPT 245 : _M_sbuf(__s), _M_failed(!_M_sbuf) { } 246 247 /// Write character to streambuf. Calls streambuf.sputc(). 248 ostreambuf_iterator& 249 operator=(_CharT __c) 250 { 251 if (!_M_failed && 252 _Traits::eq_int_type(_M_sbuf->sputc(__c), _Traits::eof())) 253 _M_failed = true; 254 return *this; 255 } 256 257 /// Return *this. 258 ostreambuf_iterator& 259 operator*() 260 { return *this; } 261 262 /// Return *this. 263 ostreambuf_iterator& 264 operator++(int) 265 { return *this; } 266 267 /// Return *this. 268 ostreambuf_iterator& 269 operator++() 270 { return *this; } 271 272 /// Return true if previous operator=() failed. 273 bool 274 failed() const _GLIBCXX_USE_NOEXCEPT 275 { return _M_failed; } 276 277 ostreambuf_iterator& 278 _M_put(const _CharT* __ws, streamsize __len) 279 { 280 if (__builtin_expect(!_M_failed, true) 281 && __builtin_expect(this->_M_sbuf->sputn(__ws, __len) != __len, 282 false)) 283 _M_failed = true; 284 return *this; 285 } 286 }; 287 288 // Overloads for streambuf iterators. 289 template<typename _CharT> 290 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, 291 ostreambuf_iterator<_CharT> >::__type 292 copy(istreambuf_iterator<_CharT> __first, 293 istreambuf_iterator<_CharT> __last, 294 ostreambuf_iterator<_CharT> __result) 295 { 296 if (__first._M_sbuf && !__last._M_sbuf && !__result._M_failed) 297 { 298 bool __ineof; 299 __copy_streambufs_eof(__first._M_sbuf, __result._M_sbuf, __ineof); 300 if (!__ineof) 301 __result._M_failed = true; 302 } 303 return __result; 304 } 305 306 template<bool _IsMove, typename _CharT> 307 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, 308 ostreambuf_iterator<_CharT> >::__type 309 __copy_move_a2(_CharT* __first, _CharT* __last, 310 ostreambuf_iterator<_CharT> __result) 311 { 312 const streamsize __num = __last - __first; 313 if (__num > 0) 314 __result._M_put(__first, __num); 315 return __result; 316 } 317 318 template<bool _IsMove, typename _CharT> 319 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, 320 ostreambuf_iterator<_CharT> >::__type 321 __copy_move_a2(const _CharT* __first, const _CharT* __last, 322 ostreambuf_iterator<_CharT> __result) 323 { 324 const streamsize __num = __last - __first; 325 if (__num > 0) 326 __result._M_put(__first, __num); 327 return __result; 328 } 329 330 template<bool _IsMove, typename _CharT> 331 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, 332 _CharT*>::__type 333 __copy_move_a2(istreambuf_iterator<_CharT> __first, 334 istreambuf_iterator<_CharT> __last, _CharT* __result) 335 { 336 typedef istreambuf_iterator<_CharT> __is_iterator_type; 337 typedef typename __is_iterator_type::traits_type traits_type; 338 typedef typename __is_iterator_type::streambuf_type streambuf_type; 339 typedef typename traits_type::int_type int_type; 340 341 if (__first._M_sbuf && !__last._M_sbuf) 342 { 343 streambuf_type* __sb = __first._M_sbuf; 344 int_type __c = __sb->sgetc(); 345 while (!traits_type::eq_int_type(__c, traits_type::eof())) 346 { 347 const streamsize __n = __sb->egptr() - __sb->gptr(); 348 if (__n > 1) 349 { 350 traits_type::copy(__result, __sb->gptr(), __n); 351 __sb->__safe_gbump(__n); 352 __result += __n; 353 __c = __sb->underflow(); 354 } 355 else 356 { 357 *__result++ = traits_type::to_char_type(__c); 358 __c = __sb->snextc(); 359 } 360 } 361 } 362 return __result; 363 } 364 365 template<typename _CharT> 366 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, 367 istreambuf_iterator<_CharT> >::__type 368 find(istreambuf_iterator<_CharT> __first, 369 istreambuf_iterator<_CharT> __last, const _CharT& __val) 370 { 371 typedef istreambuf_iterator<_CharT> __is_iterator_type; 372 typedef typename __is_iterator_type::traits_type traits_type; 373 typedef typename __is_iterator_type::streambuf_type streambuf_type; 374 typedef typename traits_type::int_type int_type; 375 const int_type __eof = traits_type::eof(); 376 377 if (__first._M_sbuf && !__last._M_sbuf) 378 { 379 const int_type __ival = traits_type::to_int_type(__val); 380 streambuf_type* __sb = __first._M_sbuf; 381 int_type __c = __sb->sgetc(); 382 while (!traits_type::eq_int_type(__c, __eof) 383 && !traits_type::eq_int_type(__c, __ival)) 384 { 385 streamsize __n = __sb->egptr() - __sb->gptr(); 386 if (__n > 1) 387 { 388 const _CharT* __p = traits_type::find(__sb->gptr(), 389 __n, __val); 390 if (__p) 391 __n = __p - __sb->gptr(); 392 __sb->__safe_gbump(__n); 393 __c = __sb->sgetc(); 394 } 395 else 396 __c = __sb->snextc(); 397 } 398 399 __first._M_c = __eof; 400 } 401 402 return __first; 403 } 404 405 template<typename _CharT, typename _Distance> 406 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, 407 void>::__type 408 advance(istreambuf_iterator<_CharT>& __i, _Distance __n) 409 { 410 if (__n == 0) 411 return; 412 413 __glibcxx_assert(__n > 0); 414 __glibcxx_requires_cond(!__i._M_at_eof(), 415 _M_message(__gnu_debug::__msg_inc_istreambuf) 416 ._M_iterator(__i)); 417 418 typedef istreambuf_iterator<_CharT> __is_iterator_type; 419 typedef typename __is_iterator_type::traits_type traits_type; 420 typedef typename __is_iterator_type::streambuf_type streambuf_type; 421 typedef typename traits_type::int_type int_type; 422 const int_type __eof = traits_type::eof(); 423 424 streambuf_type* __sb = __i._M_sbuf; 425 while (__n > 0) 426 { 427 streamsize __size = __sb->egptr() - __sb->gptr(); 428 if (__size > __n) 429 { 430 __sb->__safe_gbump(__n); 431 break; 432 } 433 434 __sb->__safe_gbump(__size); 435 __n -= __size; 436 if (traits_type::eq_int_type(__sb->underflow(), __eof)) 437 { 438 __glibcxx_requires_cond(__n == 0, 439 _M_message(__gnu_debug::__msg_inc_istreambuf) 440 ._M_iterator(__i)); 441 break; 442 } 443 } 444 445 __i._M_c = __eof; 446 } 447 448 // @} group iterators 449 450 _GLIBCXX_END_NAMESPACE_VERSION 451 } // namespace 452 453 #endif 454