libstdc++
|
00001 // String based streams -*- C++ -*- 00002 00003 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 00004 // 2006, 2008, 2009 Free Software Foundation, Inc. 00005 // 00006 // This file is part of the GNU ISO C++ Library. This library is free 00007 // software; you can redistribute it and/or modify it under the 00008 // terms of the GNU General Public License as published by the 00009 // Free Software Foundation; either version 3, or (at your option) 00010 // any later version. 00011 00012 // This library is distributed in the hope that it will be useful, 00013 // but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 00015 // GNU General Public License for more details. 00016 00017 // Under Section 7 of GPL version 3, you are granted additional 00018 // permissions described in the GCC Runtime Library Exception, version 00019 // 3.1, as published by the Free Software Foundation. 00020 00021 // You should have received a copy of the GNU General Public License and 00022 // a copy of the GCC Runtime Library Exception along with this program; 00023 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 00024 // <http://www.gnu.org/licenses/>. 00025 00026 /** @file sstream 00027 * This is a Standard C++ Library header. 00028 */ 00029 00030 // 00031 // ISO C++ 14882: 27.7 String-based streams 00032 // 00033 00034 #ifndef _GLIBCXX_SSTREAM 00035 #define _GLIBCXX_SSTREAM 1 00036 00037 #pragma GCC system_header 00038 00039 #include <istream> 00040 #include <ostream> 00041 00042 _GLIBCXX_BEGIN_NAMESPACE(std) 00043 00044 // [27.7.1] template class basic_stringbuf 00045 /** 00046 * @brief The actual work of input and output (for std::string). 00047 * @ingroup io 00048 * 00049 * This class associates either or both of its input and output sequences 00050 * with a sequence of characters, which can be initialized from, or made 00051 * available as, a @c std::basic_string. (Paraphrased from [27.7.1]/1.) 00052 * 00053 * For this class, open modes (of type @c ios_base::openmode) have 00054 * @c in set if the input sequence can be read, and @c out set if the 00055 * output sequence can be written. 00056 */ 00057 template<typename _CharT, typename _Traits, typename _Alloc> 00058 class basic_stringbuf : public basic_streambuf<_CharT, _Traits> 00059 { 00060 public: 00061 // Types: 00062 typedef _CharT char_type; 00063 typedef _Traits traits_type; 00064 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00065 // 251. basic_stringbuf missing allocator_type 00066 typedef _Alloc allocator_type; 00067 typedef typename traits_type::int_type int_type; 00068 typedef typename traits_type::pos_type pos_type; 00069 typedef typename traits_type::off_type off_type; 00070 00071 typedef basic_streambuf<char_type, traits_type> __streambuf_type; 00072 typedef basic_string<char_type, _Traits, _Alloc> __string_type; 00073 typedef typename __string_type::size_type __size_type; 00074 00075 protected: 00076 /// Place to stash in || out || in | out settings for current stringbuf. 00077 ios_base::openmode _M_mode; 00078 00079 // Data Members: 00080 __string_type _M_string; 00081 00082 public: 00083 // Constructors: 00084 /** 00085 * @brief Starts with an empty string buffer. 00086 * @param mode Whether the buffer can read, or write, or both. 00087 * 00088 * The default constructor initializes the parent class using its 00089 * own default ctor. 00090 */ 00091 explicit 00092 basic_stringbuf(ios_base::openmode __mode = ios_base::in | ios_base::out) 00093 : __streambuf_type(), _M_mode(__mode), _M_string() 00094 { } 00095 00096 /** 00097 * @brief Starts with an existing string buffer. 00098 * @param str A string to copy as a starting buffer. 00099 * @param mode Whether the buffer can read, or write, or both. 00100 * 00101 * This constructor initializes the parent class using its 00102 * own default ctor. 00103 */ 00104 explicit 00105 basic_stringbuf(const __string_type& __str, 00106 ios_base::openmode __mode = ios_base::in | ios_base::out) 00107 : __streambuf_type(), _M_mode(), _M_string(__str.data(), __str.size()) 00108 { _M_stringbuf_init(__mode); } 00109 00110 // Get and set: 00111 /** 00112 * @brief Copying out the string buffer. 00113 * @return A copy of one of the underlying sequences. 00114 * 00115 * "If the buffer is only created in input mode, the underlying 00116 * character sequence is equal to the input sequence; otherwise, it 00117 * is equal to the output sequence." [27.7.1.2]/1 00118 */ 00119 __string_type 00120 str() const 00121 { 00122 __string_type __ret; 00123 if (this->pptr()) 00124 { 00125 // The current egptr() may not be the actual string end. 00126 if (this->pptr() > this->egptr()) 00127 __ret = __string_type(this->pbase(), this->pptr()); 00128 else 00129 __ret = __string_type(this->pbase(), this->egptr()); 00130 } 00131 else 00132 __ret = _M_string; 00133 return __ret; 00134 } 00135 00136 /** 00137 * @brief Setting a new buffer. 00138 * @param s The string to use as a new sequence. 00139 * 00140 * Deallocates any previous stored sequence, then copies @a s to 00141 * use as a new one. 00142 */ 00143 void 00144 str(const __string_type& __s) 00145 { 00146 // Cannot use _M_string = __s, since v3 strings are COW. 00147 _M_string.assign(__s.data(), __s.size()); 00148 _M_stringbuf_init(_M_mode); 00149 } 00150 00151 protected: 00152 // Common initialization code goes here. 00153 void 00154 _M_stringbuf_init(ios_base::openmode __mode) 00155 { 00156 _M_mode = __mode; 00157 __size_type __len = 0; 00158 if (_M_mode & (ios_base::ate | ios_base::app)) 00159 __len = _M_string.size(); 00160 _M_sync(const_cast<char_type*>(_M_string.data()), 0, __len); 00161 } 00162 00163 virtual streamsize 00164 showmanyc() 00165 { 00166 streamsize __ret = -1; 00167 if (_M_mode & ios_base::in) 00168 { 00169 _M_update_egptr(); 00170 __ret = this->egptr() - this->gptr(); 00171 } 00172 return __ret; 00173 } 00174 00175 virtual int_type 00176 underflow(); 00177 00178 virtual int_type 00179 pbackfail(int_type __c = traits_type::eof()); 00180 00181 virtual int_type 00182 overflow(int_type __c = traits_type::eof()); 00183 00184 /** 00185 * @brief Manipulates the buffer. 00186 * @param s Pointer to a buffer area. 00187 * @param n Size of @a s. 00188 * @return @c this 00189 * 00190 * If no buffer has already been created, and both @a s and @a n are 00191 * non-zero, then @c s is used as a buffer; see 00192 * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch25s02.html 00193 * for more. 00194 */ 00195 virtual __streambuf_type* 00196 setbuf(char_type* __s, streamsize __n) 00197 { 00198 if (__s && __n >= 0) 00199 { 00200 // This is implementation-defined behavior, and assumes 00201 // that an external char_type array of length __n exists 00202 // and has been pre-allocated. If this is not the case, 00203 // things will quickly blow up. 00204 00205 // Step 1: Destroy the current internal array. 00206 _M_string.clear(); 00207 00208 // Step 2: Use the external array. 00209 _M_sync(__s, __n, 0); 00210 } 00211 return this; 00212 } 00213 00214 virtual pos_type 00215 seekoff(off_type __off, ios_base::seekdir __way, 00216 ios_base::openmode __mode = ios_base::in | ios_base::out); 00217 00218 virtual pos_type 00219 seekpos(pos_type __sp, 00220 ios_base::openmode __mode = ios_base::in | ios_base::out); 00221 00222 // Internal function for correctly updating the internal buffer 00223 // for a particular _M_string, due to initialization or re-sizing 00224 // of an existing _M_string. 00225 void 00226 _M_sync(char_type* __base, __size_type __i, __size_type __o); 00227 00228 // Internal function for correctly updating egptr() to the actual 00229 // string end. 00230 void 00231 _M_update_egptr() 00232 { 00233 const bool __testin = _M_mode & ios_base::in; 00234 if (this->pptr() && this->pptr() > this->egptr()) 00235 { 00236 if (__testin) 00237 this->setg(this->eback(), this->gptr(), this->pptr()); 00238 else 00239 this->setg(this->pptr(), this->pptr(), this->pptr()); 00240 } 00241 } 00242 }; 00243 00244 00245 // [27.7.2] Template class basic_istringstream 00246 /** 00247 * @brief Controlling input for std::string. 00248 * @ingroup io 00249 * 00250 * This class supports reading from objects of type std::basic_string, 00251 * using the inherited functions from std::basic_istream. To control 00252 * the associated sequence, an instance of std::basic_stringbuf is used, 00253 * which this page refers to as @c sb. 00254 */ 00255 template<typename _CharT, typename _Traits, typename _Alloc> 00256 class basic_istringstream : public basic_istream<_CharT, _Traits> 00257 { 00258 public: 00259 // Types: 00260 typedef _CharT char_type; 00261 typedef _Traits traits_type; 00262 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00263 // 251. basic_stringbuf missing allocator_type 00264 typedef _Alloc allocator_type; 00265 typedef typename traits_type::int_type int_type; 00266 typedef typename traits_type::pos_type pos_type; 00267 typedef typename traits_type::off_type off_type; 00268 00269 // Non-standard types: 00270 typedef basic_string<_CharT, _Traits, _Alloc> __string_type; 00271 typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type; 00272 typedef basic_istream<char_type, traits_type> __istream_type; 00273 00274 private: 00275 __stringbuf_type _M_stringbuf; 00276 00277 public: 00278 // Constructors: 00279 /** 00280 * @brief Default constructor starts with an empty string buffer. 00281 * @param mode Whether the buffer can read, or write, or both. 00282 * 00283 * @c ios_base::in is automatically included in @a mode. 00284 * 00285 * Initializes @c sb using @c mode|in, and passes @c &sb to the base 00286 * class initializer. Does not allocate any buffer. 00287 * 00288 * That's a lie. We initialize the base class with NULL, because the 00289 * string class does its own memory management. 00290 */ 00291 explicit 00292 basic_istringstream(ios_base::openmode __mode = ios_base::in) 00293 : __istream_type(), _M_stringbuf(__mode | ios_base::in) 00294 { this->init(&_M_stringbuf); } 00295 00296 /** 00297 * @brief Starts with an existing string buffer. 00298 * @param str A string to copy as a starting buffer. 00299 * @param mode Whether the buffer can read, or write, or both. 00300 * 00301 * @c ios_base::in is automatically included in @a mode. 00302 * 00303 * Initializes @c sb using @a str and @c mode|in, and passes @c &sb 00304 * to the base class initializer. 00305 * 00306 * That's a lie. We initialize the base class with NULL, because the 00307 * string class does its own memory management. 00308 */ 00309 explicit 00310 basic_istringstream(const __string_type& __str, 00311 ios_base::openmode __mode = ios_base::in) 00312 : __istream_type(), _M_stringbuf(__str, __mode | ios_base::in) 00313 { this->init(&_M_stringbuf); } 00314 00315 /** 00316 * @brief The destructor does nothing. 00317 * 00318 * The buffer is deallocated by the stringbuf object, not the 00319 * formatting stream. 00320 */ 00321 ~basic_istringstream() 00322 { } 00323 00324 // Members: 00325 /** 00326 * @brief Accessing the underlying buffer. 00327 * @return The current basic_stringbuf buffer. 00328 * 00329 * This hides both signatures of std::basic_ios::rdbuf(). 00330 */ 00331 __stringbuf_type* 00332 rdbuf() const 00333 { return const_cast<__stringbuf_type*>(&_M_stringbuf); } 00334 00335 /** 00336 * @brief Copying out the string buffer. 00337 * @return @c rdbuf()->str() 00338 */ 00339 __string_type 00340 str() const 00341 { return _M_stringbuf.str(); } 00342 00343 /** 00344 * @brief Setting a new buffer. 00345 * @param s The string to use as a new sequence. 00346 * 00347 * Calls @c rdbuf()->str(s). 00348 */ 00349 void 00350 str(const __string_type& __s) 00351 { _M_stringbuf.str(__s); } 00352 }; 00353 00354 00355 // [27.7.3] Template class basic_ostringstream 00356 /** 00357 * @brief Controlling output for std::string. 00358 * @ingroup io 00359 * 00360 * This class supports writing to objects of type std::basic_string, 00361 * using the inherited functions from std::basic_ostream. To control 00362 * the associated sequence, an instance of std::basic_stringbuf is used, 00363 * which this page refers to as @c sb. 00364 */ 00365 template <typename _CharT, typename _Traits, typename _Alloc> 00366 class basic_ostringstream : public basic_ostream<_CharT, _Traits> 00367 { 00368 public: 00369 // Types: 00370 typedef _CharT char_type; 00371 typedef _Traits traits_type; 00372 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00373 // 251. basic_stringbuf missing allocator_type 00374 typedef _Alloc allocator_type; 00375 typedef typename traits_type::int_type int_type; 00376 typedef typename traits_type::pos_type pos_type; 00377 typedef typename traits_type::off_type off_type; 00378 00379 // Non-standard types: 00380 typedef basic_string<_CharT, _Traits, _Alloc> __string_type; 00381 typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type; 00382 typedef basic_ostream<char_type, traits_type> __ostream_type; 00383 00384 private: 00385 __stringbuf_type _M_stringbuf; 00386 00387 public: 00388 // Constructors/destructor: 00389 /** 00390 * @brief Default constructor starts with an empty string buffer. 00391 * @param mode Whether the buffer can read, or write, or both. 00392 * 00393 * @c ios_base::out is automatically included in @a mode. 00394 * 00395 * Initializes @c sb using @c mode|out, and passes @c &sb to the base 00396 * class initializer. Does not allocate any buffer. 00397 * 00398 * That's a lie. We initialize the base class with NULL, because the 00399 * string class does its own memory management. 00400 */ 00401 explicit 00402 basic_ostringstream(ios_base::openmode __mode = ios_base::out) 00403 : __ostream_type(), _M_stringbuf(__mode | ios_base::out) 00404 { this->init(&_M_stringbuf); } 00405 00406 /** 00407 * @brief Starts with an existing string buffer. 00408 * @param str A string to copy as a starting buffer. 00409 * @param mode Whether the buffer can read, or write, or both. 00410 * 00411 * @c ios_base::out is automatically included in @a mode. 00412 * 00413 * Initializes @c sb using @a str and @c mode|out, and passes @c &sb 00414 * to the base class initializer. 00415 * 00416 * That's a lie. We initialize the base class with NULL, because the 00417 * string class does its own memory management. 00418 */ 00419 explicit 00420 basic_ostringstream(const __string_type& __str, 00421 ios_base::openmode __mode = ios_base::out) 00422 : __ostream_type(), _M_stringbuf(__str, __mode | ios_base::out) 00423 { this->init(&_M_stringbuf); } 00424 00425 /** 00426 * @brief The destructor does nothing. 00427 * 00428 * The buffer is deallocated by the stringbuf object, not the 00429 * formatting stream. 00430 */ 00431 ~basic_ostringstream() 00432 { } 00433 00434 // Members: 00435 /** 00436 * @brief Accessing the underlying buffer. 00437 * @return The current basic_stringbuf buffer. 00438 * 00439 * This hides both signatures of std::basic_ios::rdbuf(). 00440 */ 00441 __stringbuf_type* 00442 rdbuf() const 00443 { return const_cast<__stringbuf_type*>(&_M_stringbuf); } 00444 00445 /** 00446 * @brief Copying out the string buffer. 00447 * @return @c rdbuf()->str() 00448 */ 00449 __string_type 00450 str() const 00451 { return _M_stringbuf.str(); } 00452 00453 /** 00454 * @brief Setting a new buffer. 00455 * @param s The string to use as a new sequence. 00456 * 00457 * Calls @c rdbuf()->str(s). 00458 */ 00459 void 00460 str(const __string_type& __s) 00461 { _M_stringbuf.str(__s); } 00462 }; 00463 00464 00465 // [27.7.4] Template class basic_stringstream 00466 /** 00467 * @brief Controlling input and output for std::string. 00468 * @ingroup io 00469 * 00470 * This class supports reading from and writing to objects of type 00471 * std::basic_string, using the inherited functions from 00472 * std::basic_iostream. To control the associated sequence, an instance 00473 * of std::basic_stringbuf is used, which this page refers to as @c sb. 00474 */ 00475 template <typename _CharT, typename _Traits, typename _Alloc> 00476 class basic_stringstream : public basic_iostream<_CharT, _Traits> 00477 { 00478 public: 00479 // Types: 00480 typedef _CharT char_type; 00481 typedef _Traits traits_type; 00482 // _GLIBCXX_RESOLVE_LIB_DEFECTS 00483 // 251. basic_stringbuf missing allocator_type 00484 typedef _Alloc allocator_type; 00485 typedef typename traits_type::int_type int_type; 00486 typedef typename traits_type::pos_type pos_type; 00487 typedef typename traits_type::off_type off_type; 00488 00489 // Non-standard Types: 00490 typedef basic_string<_CharT, _Traits, _Alloc> __string_type; 00491 typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type; 00492 typedef basic_iostream<char_type, traits_type> __iostream_type; 00493 00494 private: 00495 __stringbuf_type _M_stringbuf; 00496 00497 public: 00498 // Constructors/destructors 00499 /** 00500 * @brief Default constructor starts with an empty string buffer. 00501 * @param mode Whether the buffer can read, or write, or both. 00502 * 00503 * Initializes @c sb using @c mode, and passes @c &sb to the base 00504 * class initializer. Does not allocate any buffer. 00505 * 00506 * That's a lie. We initialize the base class with NULL, because the 00507 * string class does its own memory management. 00508 */ 00509 explicit 00510 basic_stringstream(ios_base::openmode __m = ios_base::out | ios_base::in) 00511 : __iostream_type(), _M_stringbuf(__m) 00512 { this->init(&_M_stringbuf); } 00513 00514 /** 00515 * @brief Starts with an existing string buffer. 00516 * @param str A string to copy as a starting buffer. 00517 * @param mode Whether the buffer can read, or write, or both. 00518 * 00519 * Initializes @c sb using @a str and @c mode, and passes @c &sb 00520 * to the base class initializer. 00521 * 00522 * That's a lie. We initialize the base class with NULL, because the 00523 * string class does its own memory management. 00524 */ 00525 explicit 00526 basic_stringstream(const __string_type& __str, 00527 ios_base::openmode __m = ios_base::out | ios_base::in) 00528 : __iostream_type(), _M_stringbuf(__str, __m) 00529 { this->init(&_M_stringbuf); } 00530 00531 /** 00532 * @brief The destructor does nothing. 00533 * 00534 * The buffer is deallocated by the stringbuf object, not the 00535 * formatting stream. 00536 */ 00537 ~basic_stringstream() 00538 { } 00539 00540 // Members: 00541 /** 00542 * @brief Accessing the underlying buffer. 00543 * @return The current basic_stringbuf buffer. 00544 * 00545 * This hides both signatures of std::basic_ios::rdbuf(). 00546 */ 00547 __stringbuf_type* 00548 rdbuf() const 00549 { return const_cast<__stringbuf_type*>(&_M_stringbuf); } 00550 00551 /** 00552 * @brief Copying out the string buffer. 00553 * @return @c rdbuf()->str() 00554 */ 00555 __string_type 00556 str() const 00557 { return _M_stringbuf.str(); } 00558 00559 /** 00560 * @brief Setting a new buffer. 00561 * @param s The string to use as a new sequence. 00562 * 00563 * Calls @c rdbuf()->str(s). 00564 */ 00565 void 00566 str(const __string_type& __s) 00567 { _M_stringbuf.str(__s); } 00568 }; 00569 00570 _GLIBCXX_END_NAMESPACE 00571 00572 #ifndef _GLIBCXX_EXPORT_TEMPLATE 00573 # include <bits/sstream.tcc> 00574 #endif 00575 00576 #endif /* _GLIBCXX_SSTREAM */