libstdc++
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00001 // Streambuf iterators 00002 00003 // Copyright (C) 1997-2015 Free Software Foundation, Inc. 00004 // 00005 // This file is part of the GNU ISO C++ Library. This library is free 00006 // software; you can redistribute it and/or modify it under the 00007 // terms of the GNU General Public License as published by the 00008 // Free Software Foundation; either version 3, or (at your option) 00009 // any later version. 00010 00011 // This library is distributed in the hope that it will be useful, 00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00014 // GNU General Public License for more details. 00015 00016 // Under Section 7 of GPL version 3, you are granted additional 00017 // permissions described in the GCC Runtime Library Exception, version 00018 // 3.1, as published by the Free Software Foundation. 00019 00020 // You should have received a copy of the GNU General Public License and 00021 // a copy of the GCC Runtime Library Exception along with this program; 00022 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00023 // <http://www.gnu.org/licenses/>. 00024 00025 /** @file bits/streambuf_iterator.h 00026 * This is an internal header file, included by other library headers. 00027 * Do not attempt to use it directly. @headername{iterator} 00028 */ 00029 00030 #ifndef _STREAMBUF_ITERATOR_H 00031 #define _STREAMBUF_ITERATOR_H 1 00032 00033 #pragma GCC system_header 00034 00035 #include <streambuf> 00036 #include <debug/debug.h> 00037 00038 namespace std _GLIBCXX_VISIBILITY(default) 00039 { 00040 _GLIBCXX_BEGIN_NAMESPACE_VERSION 00041 00042 /** 00043 * @addtogroup iterators 00044 * @{ 00045 */ 00046 00047 // 24.5.3 Template class istreambuf_iterator 00048 /// Provides input iterator semantics for streambufs. 00049 template<typename _CharT, typename _Traits> 00050 class istreambuf_iterator 00051 : public iterator<input_iterator_tag, _CharT, typename _Traits::off_type, 00052 _CharT*, 00053 #if __cplusplus >= 201103L 00054 // LWG 445. 00055 _CharT> 00056 #else 00057 _CharT&> 00058 #endif 00059 { 00060 public: 00061 // Types: 00062 //@{ 00063 /// Public typedefs 00064 typedef _CharT char_type; 00065 typedef _Traits traits_type; 00066 typedef typename _Traits::int_type int_type; 00067 typedef basic_streambuf<_CharT, _Traits> streambuf_type; 00068 typedef basic_istream<_CharT, _Traits> istream_type; 00069 //@} 00070 00071 template<typename _CharT2> 00072 friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, 00073 ostreambuf_iterator<_CharT2> >::__type 00074 copy(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>, 00075 ostreambuf_iterator<_CharT2>); 00076 00077 template<bool _IsMove, typename _CharT2> 00078 friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, 00079 _CharT2*>::__type 00080 __copy_move_a2(istreambuf_iterator<_CharT2>, 00081 istreambuf_iterator<_CharT2>, _CharT2*); 00082 00083 template<typename _CharT2> 00084 friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, 00085 istreambuf_iterator<_CharT2> >::__type 00086 find(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>, 00087 const _CharT2&); 00088 00089 private: 00090 // 24.5.3 istreambuf_iterator 00091 // p 1 00092 // If the end of stream is reached (streambuf_type::sgetc() 00093 // returns traits_type::eof()), the iterator becomes equal to 00094 // the "end of stream" iterator value. 00095 // NB: This implementation assumes the "end of stream" value 00096 // is EOF, or -1. 00097 mutable streambuf_type* _M_sbuf; 00098 mutable int_type _M_c; 00099 00100 public: 00101 /// Construct end of input stream iterator. 00102 _GLIBCXX_CONSTEXPR istreambuf_iterator() _GLIBCXX_USE_NOEXCEPT 00103 : _M_sbuf(0), _M_c(traits_type::eof()) { } 00104 00105 #if __cplusplus >= 201103L 00106 istreambuf_iterator(const istreambuf_iterator&) noexcept = default; 00107 00108 ~istreambuf_iterator() = default; 00109 #endif 00110 00111 /// Construct start of input stream iterator. 00112 istreambuf_iterator(istream_type& __s) _GLIBCXX_USE_NOEXCEPT 00113 : _M_sbuf(__s.rdbuf()), _M_c(traits_type::eof()) { } 00114 00115 /// Construct start of streambuf iterator. 00116 istreambuf_iterator(streambuf_type* __s) _GLIBCXX_USE_NOEXCEPT 00117 : _M_sbuf(__s), _M_c(traits_type::eof()) { } 00118 00119 /// Return the current character pointed to by iterator. This returns 00120 /// streambuf.sgetc(). It cannot be assigned. NB: The result of 00121 /// operator*() on an end of stream is undefined. 00122 char_type 00123 operator*() const 00124 { 00125 #ifdef _GLIBCXX_DEBUG_PEDANTIC 00126 // Dereferencing a past-the-end istreambuf_iterator is a 00127 // libstdc++ extension 00128 __glibcxx_requires_cond(!_M_at_eof(), 00129 _M_message(__gnu_debug::__msg_deref_istreambuf) 00130 ._M_iterator(*this)); 00131 #endif 00132 return traits_type::to_char_type(_M_get()); 00133 } 00134 00135 /// Advance the iterator. Calls streambuf.sbumpc(). 00136 istreambuf_iterator& 00137 operator++() 00138 { 00139 __glibcxx_requires_cond(!_M_at_eof(), 00140 _M_message(__gnu_debug::__msg_inc_istreambuf) 00141 ._M_iterator(*this)); 00142 if (_M_sbuf) 00143 { 00144 _M_sbuf->sbumpc(); 00145 _M_c = traits_type::eof(); 00146 } 00147 return *this; 00148 } 00149 00150 /// Advance the iterator. Calls streambuf.sbumpc(). 00151 istreambuf_iterator 00152 operator++(int) 00153 { 00154 __glibcxx_requires_cond(!_M_at_eof(), 00155 _M_message(__gnu_debug::__msg_inc_istreambuf) 00156 ._M_iterator(*this)); 00157 00158 istreambuf_iterator __old = *this; 00159 if (_M_sbuf) 00160 { 00161 __old._M_c = _M_sbuf->sbumpc(); 00162 _M_c = traits_type::eof(); 00163 } 00164 return __old; 00165 } 00166 00167 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00168 // 110 istreambuf_iterator::equal not const 00169 // NB: there is also number 111 (NAD, Future) pending on this function. 00170 /// Return true both iterators are end or both are not end. 00171 bool 00172 equal(const istreambuf_iterator& __b) const 00173 { return _M_at_eof() == __b._M_at_eof(); } 00174 00175 private: 00176 int_type 00177 _M_get() const 00178 { 00179 const int_type __eof = traits_type::eof(); 00180 int_type __ret = __eof; 00181 if (_M_sbuf) 00182 { 00183 if (!traits_type::eq_int_type(_M_c, __eof)) 00184 __ret = _M_c; 00185 else if (!traits_type::eq_int_type((__ret = _M_sbuf->sgetc()), 00186 __eof)) 00187 _M_c = __ret; 00188 else 00189 _M_sbuf = 0; 00190 } 00191 return __ret; 00192 } 00193 00194 bool 00195 _M_at_eof() const 00196 { 00197 const int_type __eof = traits_type::eof(); 00198 return traits_type::eq_int_type(_M_get(), __eof); 00199 } 00200 }; 00201 00202 template<typename _CharT, typename _Traits> 00203 inline bool 00204 operator==(const istreambuf_iterator<_CharT, _Traits>& __a, 00205 const istreambuf_iterator<_CharT, _Traits>& __b) 00206 { return __a.equal(__b); } 00207 00208 template<typename _CharT, typename _Traits> 00209 inline bool 00210 operator!=(const istreambuf_iterator<_CharT, _Traits>& __a, 00211 const istreambuf_iterator<_CharT, _Traits>& __b) 00212 { return !__a.equal(__b); } 00213 00214 /// Provides output iterator semantics for streambufs. 00215 template<typename _CharT, typename _Traits> 00216 class ostreambuf_iterator 00217 : public iterator<output_iterator_tag, void, void, void, void> 00218 { 00219 public: 00220 // Types: 00221 //@{ 00222 /// Public typedefs 00223 typedef _CharT char_type; 00224 typedef _Traits traits_type; 00225 typedef basic_streambuf<_CharT, _Traits> streambuf_type; 00226 typedef basic_ostream<_CharT, _Traits> ostream_type; 00227 //@} 00228 00229 template<typename _CharT2> 00230 friend typename __gnu_cxx::__enable_if<__is_char<_CharT2>::__value, 00231 ostreambuf_iterator<_CharT2> >::__type 00232 copy(istreambuf_iterator<_CharT2>, istreambuf_iterator<_CharT2>, 00233 ostreambuf_iterator<_CharT2>); 00234 00235 private: 00236 streambuf_type* _M_sbuf; 00237 bool _M_failed; 00238 00239 public: 00240 /// Construct output iterator from ostream. 00241 ostreambuf_iterator(ostream_type& __s) _GLIBCXX_USE_NOEXCEPT 00242 : _M_sbuf(__s.rdbuf()), _M_failed(!_M_sbuf) { } 00243 00244 /// Construct output iterator from streambuf. 00245 ostreambuf_iterator(streambuf_type* __s) _GLIBCXX_USE_NOEXCEPT 00246 : _M_sbuf(__s), _M_failed(!_M_sbuf) { } 00247 00248 /// Write character to streambuf. Calls streambuf.sputc(). 00249 ostreambuf_iterator& 00250 operator=(_CharT __c) 00251 { 00252 if (!_M_failed && 00253 _Traits::eq_int_type(_M_sbuf->sputc(__c), _Traits::eof())) 00254 _M_failed = true; 00255 return *this; 00256 } 00257 00258 /// Return *this. 00259 ostreambuf_iterator& 00260 operator*() 00261 { return *this; } 00262 00263 /// Return *this. 00264 ostreambuf_iterator& 00265 operator++(int) 00266 { return *this; } 00267 00268 /// Return *this. 00269 ostreambuf_iterator& 00270 operator++() 00271 { return *this; } 00272 00273 /// Return true if previous operator=() failed. 00274 bool 00275 failed() const _GLIBCXX_USE_NOEXCEPT 00276 { return _M_failed; } 00277 00278 ostreambuf_iterator& 00279 _M_put(const _CharT* __ws, streamsize __len) 00280 { 00281 if (__builtin_expect(!_M_failed, true) 00282 && __builtin_expect(this->_M_sbuf->sputn(__ws, __len) != __len, 00283 false)) 00284 _M_failed = true; 00285 return *this; 00286 } 00287 }; 00288 00289 // Overloads for streambuf iterators. 00290 template<typename _CharT> 00291 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, 00292 ostreambuf_iterator<_CharT> >::__type 00293 copy(istreambuf_iterator<_CharT> __first, 00294 istreambuf_iterator<_CharT> __last, 00295 ostreambuf_iterator<_CharT> __result) 00296 { 00297 if (__first._M_sbuf && !__last._M_sbuf && !__result._M_failed) 00298 { 00299 bool __ineof; 00300 __copy_streambufs_eof(__first._M_sbuf, __result._M_sbuf, __ineof); 00301 if (!__ineof) 00302 __result._M_failed = true; 00303 } 00304 return __result; 00305 } 00306 00307 template<bool _IsMove, typename _CharT> 00308 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, 00309 ostreambuf_iterator<_CharT> >::__type 00310 __copy_move_a2(_CharT* __first, _CharT* __last, 00311 ostreambuf_iterator<_CharT> __result) 00312 { 00313 const streamsize __num = __last - __first; 00314 if (__num > 0) 00315 __result._M_put(__first, __num); 00316 return __result; 00317 } 00318 00319 template<bool _IsMove, typename _CharT> 00320 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, 00321 ostreambuf_iterator<_CharT> >::__type 00322 __copy_move_a2(const _CharT* __first, const _CharT* __last, 00323 ostreambuf_iterator<_CharT> __result) 00324 { 00325 const streamsize __num = __last - __first; 00326 if (__num > 0) 00327 __result._M_put(__first, __num); 00328 return __result; 00329 } 00330 00331 template<bool _IsMove, typename _CharT> 00332 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, 00333 _CharT*>::__type 00334 __copy_move_a2(istreambuf_iterator<_CharT> __first, 00335 istreambuf_iterator<_CharT> __last, _CharT* __result) 00336 { 00337 typedef istreambuf_iterator<_CharT> __is_iterator_type; 00338 typedef typename __is_iterator_type::traits_type traits_type; 00339 typedef typename __is_iterator_type::streambuf_type streambuf_type; 00340 typedef typename traits_type::int_type int_type; 00341 00342 if (__first._M_sbuf && !__last._M_sbuf) 00343 { 00344 streambuf_type* __sb = __first._M_sbuf; 00345 int_type __c = __sb->sgetc(); 00346 while (!traits_type::eq_int_type(__c, traits_type::eof())) 00347 { 00348 const streamsize __n = __sb->egptr() - __sb->gptr(); 00349 if (__n > 1) 00350 { 00351 traits_type::copy(__result, __sb->gptr(), __n); 00352 __sb->__safe_gbump(__n); 00353 __result += __n; 00354 __c = __sb->underflow(); 00355 } 00356 else 00357 { 00358 *__result++ = traits_type::to_char_type(__c); 00359 __c = __sb->snextc(); 00360 } 00361 } 00362 } 00363 return __result; 00364 } 00365 00366 template<typename _CharT> 00367 typename __gnu_cxx::__enable_if<__is_char<_CharT>::__value, 00368 istreambuf_iterator<_CharT> >::__type 00369 find(istreambuf_iterator<_CharT> __first, 00370 istreambuf_iterator<_CharT> __last, const _CharT& __val) 00371 { 00372 typedef istreambuf_iterator<_CharT> __is_iterator_type; 00373 typedef typename __is_iterator_type::traits_type traits_type; 00374 typedef typename __is_iterator_type::streambuf_type streambuf_type; 00375 typedef typename traits_type::int_type int_type; 00376 00377 if (__first._M_sbuf && !__last._M_sbuf) 00378 { 00379 const int_type __ival = traits_type::to_int_type(__val); 00380 streambuf_type* __sb = __first._M_sbuf; 00381 int_type __c = __sb->sgetc(); 00382 while (!traits_type::eq_int_type(__c, traits_type::eof()) 00383 && !traits_type::eq_int_type(__c, __ival)) 00384 { 00385 streamsize __n = __sb->egptr() - __sb->gptr(); 00386 if (__n > 1) 00387 { 00388 const _CharT* __p = traits_type::find(__sb->gptr(), 00389 __n, __val); 00390 if (__p) 00391 __n = __p - __sb->gptr(); 00392 __sb->__safe_gbump(__n); 00393 __c = __sb->sgetc(); 00394 } 00395 else 00396 __c = __sb->snextc(); 00397 } 00398 00399 if (!traits_type::eq_int_type(__c, traits_type::eof())) 00400 __first._M_c = __c; 00401 else 00402 __first._M_sbuf = 0; 00403 } 00404 return __first; 00405 } 00406 00407 // @} group iterators 00408 00409 _GLIBCXX_END_NAMESPACE_VERSION 00410 } // namespace 00411 00412 #endif