1// String based streams -*- C++ -*- 2 3// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 4// 2006, 2008, 2009, 2010 Free Software Foundation, Inc. 5// 6// This file is part of the GNU ISO C++ Library. This library is free 7// software; you can redistribute it and/or modify it under the 8// terms of the GNU General Public License as published by the 9// Free Software Foundation; either version 3, or (at your option) 10// any later version. 11 12// This library is distributed in the hope that it will be useful, 13// but WITHOUT ANY WARRANTY; without even the implied warranty of 14// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15// GNU General Public License for more details. 16 17// Under Section 7 of GPL version 3, you are granted additional 18// permissions described in the GCC Runtime Library Exception, version 19// 3.1, as published by the Free Software Foundation. 20 21// You should have received a copy of the GNU General Public License and 22// a copy of the GCC Runtime Library Exception along with this program; 23// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 24// <http://www.gnu.org/licenses/>. 25 26/** @file sstream 27 * This is a Standard C++ Library header. 28 */ 29 30// 31// ISO C++ 14882: 27.7 String-based streams 32// 33 34#ifndef _GLIBCXX_SSTREAM 35#define _GLIBCXX_SSTREAM 1 36 37#pragma GCC system_header 38 39#include <istream> 40#include <ostream> 41 42_GLIBCXX_BEGIN_NAMESPACE(std) 43 44 // [27.7.1] template class basic_stringbuf 45 /** 46 * @brief The actual work of input and output (for std::string). 47 * @ingroup io 48 * 49 * This class associates either or both of its input and output sequences 50 * with a sequence of characters, which can be initialized from, or made 51 * available as, a @c std::basic_string. (Paraphrased from [27.7.1]/1.) 52 * 53 * For this class, open modes (of type @c ios_base::openmode) have 54 * @c in set if the input sequence can be read, and @c out set if the 55 * output sequence can be written. 56 */ 57 template<typename _CharT, typename _Traits, typename _Alloc> 58 class basic_stringbuf : public basic_streambuf<_CharT, _Traits> 59 { 60 public: 61 // Types: 62 typedef _CharT char_type; 63 typedef _Traits traits_type; 64 // _GLIBCXX_RESOLVE_LIB_DEFECTS 65 // 251. basic_stringbuf missing allocator_type 66 typedef _Alloc allocator_type; 67 typedef typename traits_type::int_type int_type; 68 typedef typename traits_type::pos_type pos_type; 69 typedef typename traits_type::off_type off_type; 70 71 typedef basic_streambuf<char_type, traits_type> __streambuf_type; 72 typedef basic_string<char_type, _Traits, _Alloc> __string_type; 73 typedef typename __string_type::size_type __size_type; 74 75 protected: 76 /// Place to stash in || out || in | out settings for current stringbuf. 77 ios_base::openmode _M_mode; 78 79 // Data Members: 80 __string_type _M_string; 81 82 public: 83 // Constructors: 84 /** 85 * @brief Starts with an empty string buffer. 86 * @param mode Whether the buffer can read, or write, or both. 87 * 88 * The default constructor initializes the parent class using its 89 * own default ctor. 90 */ 91 explicit 92 basic_stringbuf(ios_base::openmode __mode = ios_base::in | ios_base::out) 93 : __streambuf_type(), _M_mode(__mode), _M_string() 94 { } 95 96 /** 97 * @brief Starts with an existing string buffer. 98 * @param str A string to copy as a starting buffer. 99 * @param mode Whether the buffer can read, or write, or both. 100 * 101 * This constructor initializes the parent class using its 102 * own default ctor. 103 */ 104 explicit 105 basic_stringbuf(const __string_type& __str, 106 ios_base::openmode __mode = ios_base::in | ios_base::out) 107 : __streambuf_type(), _M_mode(), _M_string(__str.data(), __str.size()) 108 { _M_stringbuf_init(__mode); } 109 110 // Get and set: 111 /** 112 * @brief Copying out the string buffer. 113 * @return A copy of one of the underlying sequences. 114 * 115 * <em>If the buffer is only created in input mode, the underlying 116 * character sequence is equal to the input sequence; otherwise, it 117 * is equal to the output sequence.</em> [27.7.1.2]/1 118 */ 119 __string_type 120 str() const 121 { 122 __string_type __ret; 123 if (this->pptr()) 124 { 125 // The current egptr() may not be the actual string end. 126 if (this->pptr() > this->egptr()) 127 __ret = __string_type(this->pbase(), this->pptr()); 128 else 129 __ret = __string_type(this->pbase(), this->egptr()); 130 } 131 else 132 __ret = _M_string; 133 return __ret; 134 } 135 136 /** 137 * @brief Setting a new buffer. 138 * @param s The string to use as a new sequence. 139 * 140 * Deallocates any previous stored sequence, then copies @a s to 141 * use as a new one. 142 */ 143 void 144 str(const __string_type& __s) 145 { 146 // Cannot use _M_string = __s, since v3 strings are COW. 147 _M_string.assign(__s.data(), __s.size()); 148 _M_stringbuf_init(_M_mode); 149 } 150 151 protected: 152 // Common initialization code goes here. 153 void 154 _M_stringbuf_init(ios_base::openmode __mode) 155 { 156 _M_mode = __mode; 157 __size_type __len = 0; 158 if (_M_mode & (ios_base::ate | ios_base::app)) 159 __len = _M_string.size(); 160 _M_sync(const_cast<char_type*>(_M_string.data()), 0, __len); 161 } 162 163 virtual streamsize 164 showmanyc() 165 { 166 streamsize __ret = -1; 167 if (_M_mode & ios_base::in) 168 { 169 _M_update_egptr(); 170 __ret = this->egptr() - this->gptr(); 171 } 172 return __ret; 173 } 174 175 virtual int_type 176 underflow(); 177 178 virtual int_type 179 pbackfail(int_type __c = traits_type::eof()); 180 181 virtual int_type 182 overflow(int_type __c = traits_type::eof()); 183 184 /** 185 * @brief Manipulates the buffer. 186 * @param s Pointer to a buffer area. 187 * @param n Size of @a s. 188 * @return @c this 189 * 190 * If no buffer has already been created, and both @a s and @a n are 191 * non-zero, then @c s is used as a buffer; see 192 * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt11ch25s02.html 193 * for more. 194 */ 195 virtual __streambuf_type* 196 setbuf(char_type* __s, streamsize __n) 197 { 198 if (__s && __n >= 0) 199 { 200 // This is implementation-defined behavior, and assumes 201 // that an external char_type array of length __n exists 202 // and has been pre-allocated. If this is not the case, 203 // things will quickly blow up. 204 205 // Step 1: Destroy the current internal array. 206 _M_string.clear(); 207 208 // Step 2: Use the external array. 209 _M_sync(__s, __n, 0); 210 } 211 return this; 212 } 213 214 virtual pos_type 215 seekoff(off_type __off, ios_base::seekdir __way, 216 ios_base::openmode __mode = ios_base::in | ios_base::out); 217 218 virtual pos_type 219 seekpos(pos_type __sp, 220 ios_base::openmode __mode = ios_base::in | ios_base::out); 221 222 // Internal function for correctly updating the internal buffer 223 // for a particular _M_string, due to initialization or re-sizing 224 // of an existing _M_string. 225 void 226 _M_sync(char_type* __base, __size_type __i, __size_type __o); 227 228 // Internal function for correctly updating egptr() to the actual 229 // string end. 230 void 231 _M_update_egptr() 232 { 233 const bool __testin = _M_mode & ios_base::in; 234 if (this->pptr() && this->pptr() > this->egptr()) 235 { 236 if (__testin) 237 this->setg(this->eback(), this->gptr(), this->pptr()); 238 else 239 this->setg(this->pptr(), this->pptr(), this->pptr()); 240 } 241 } 242 }; 243 244 245 // [27.7.2] Template class basic_istringstream 246 /** 247 * @brief Controlling input for std::string. 248 * @ingroup io 249 * 250 * This class supports reading from objects of type std::basic_string, 251 * using the inherited functions from std::basic_istream. To control 252 * the associated sequence, an instance of std::basic_stringbuf is used, 253 * which this page refers to as @c sb. 254 */ 255 template<typename _CharT, typename _Traits, typename _Alloc> 256 class basic_istringstream : public basic_istream<_CharT, _Traits> 257 { 258 public: 259 // Types: 260 typedef _CharT char_type; 261 typedef _Traits traits_type; 262 // _GLIBCXX_RESOLVE_LIB_DEFECTS 263 // 251. basic_stringbuf missing allocator_type 264 typedef _Alloc allocator_type; 265 typedef typename traits_type::int_type int_type; 266 typedef typename traits_type::pos_type pos_type; 267 typedef typename traits_type::off_type off_type; 268 269 // Non-standard types: 270 typedef basic_string<_CharT, _Traits, _Alloc> __string_type; 271 typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type; 272 typedef basic_istream<char_type, traits_type> __istream_type; 273 274 private: 275 __stringbuf_type _M_stringbuf; 276 277 public: 278 // Constructors: 279 /** 280 * @brief Default constructor starts with an empty string buffer. 281 * @param mode Whether the buffer can read, or write, or both. 282 * 283 * @c ios_base::in is automatically included in @a mode. 284 * 285 * Initializes @c sb using @c mode|in, and passes @c &sb to the base 286 * class initializer. Does not allocate any buffer. 287 * 288 * That's a lie. We initialize the base class with NULL, because the 289 * string class does its own memory management. 290 */ 291 explicit 292 basic_istringstream(ios_base::openmode __mode = ios_base::in) 293 : __istream_type(), _M_stringbuf(__mode | ios_base::in) 294 { this->init(&_M_stringbuf); } 295 296 /** 297 * @brief Starts with an existing string buffer. 298 * @param str A string to copy as a starting buffer. 299 * @param mode Whether the buffer can read, or write, or both. 300 * 301 * @c ios_base::in is automatically included in @a mode. 302 * 303 * Initializes @c sb using @a str and @c mode|in, and passes @c &sb 304 * to the base class initializer. 305 * 306 * That's a lie. We initialize the base class with NULL, because the 307 * string class does its own memory management. 308 */ 309 explicit 310 basic_istringstream(const __string_type& __str, 311 ios_base::openmode __mode = ios_base::in) 312 : __istream_type(), _M_stringbuf(__str, __mode | ios_base::in) 313 { this->init(&_M_stringbuf); } 314 315 /** 316 * @brief The destructor does nothing. 317 * 318 * The buffer is deallocated by the stringbuf object, not the 319 * formatting stream. 320 */ 321 ~basic_istringstream() 322 { } 323 324 // Members: 325 /** 326 * @brief Accessing the underlying buffer. 327 * @return The current basic_stringbuf buffer. 328 * 329 * This hides both signatures of std::basic_ios::rdbuf(). 330 */ 331 __stringbuf_type* 332 rdbuf() const 333 { return const_cast<__stringbuf_type*>(&_M_stringbuf); } 334 335 /** 336 * @brief Copying out the string buffer. 337 * @return @c rdbuf()->str() 338 */ 339 __string_type 340 str() const 341 { return _M_stringbuf.str(); } 342 343 /** 344 * @brief Setting a new buffer. 345 * @param s The string to use as a new sequence. 346 * 347 * Calls @c rdbuf()->str(s). 348 */ 349 void 350 str(const __string_type& __s) 351 { _M_stringbuf.str(__s); } 352 }; 353 354 355 // [27.7.3] Template class basic_ostringstream 356 /** 357 * @brief Controlling output for std::string. 358 * @ingroup io 359 * 360 * This class supports writing to objects of type std::basic_string, 361 * using the inherited functions from std::basic_ostream. To control 362 * the associated sequence, an instance of std::basic_stringbuf is used, 363 * which this page refers to as @c sb. 364 */ 365 template <typename _CharT, typename _Traits, typename _Alloc> 366 class basic_ostringstream : public basic_ostream<_CharT, _Traits> 367 { 368 public: 369 // Types: 370 typedef _CharT char_type; 371 typedef _Traits traits_type; 372 // _GLIBCXX_RESOLVE_LIB_DEFECTS 373 // 251. basic_stringbuf missing allocator_type 374 typedef _Alloc allocator_type; 375 typedef typename traits_type::int_type int_type; 376 typedef typename traits_type::pos_type pos_type; 377 typedef typename traits_type::off_type off_type; 378 379 // Non-standard types: 380 typedef basic_string<_CharT, _Traits, _Alloc> __string_type; 381 typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type; 382 typedef basic_ostream<char_type, traits_type> __ostream_type; 383 384 private: 385 __stringbuf_type _M_stringbuf; 386 387 public: 388 // Constructors/destructor: 389 /** 390 * @brief Default constructor starts with an empty string buffer. 391 * @param mode Whether the buffer can read, or write, or both. 392 * 393 * @c ios_base::out is automatically included in @a mode. 394 * 395 * Initializes @c sb using @c mode|out, and passes @c &sb to the base 396 * class initializer. Does not allocate any buffer. 397 * 398 * That's a lie. We initialize the base class with NULL, because the 399 * string class does its own memory management. 400 */ 401 explicit 402 basic_ostringstream(ios_base::openmode __mode = ios_base::out) 403 : __ostream_type(), _M_stringbuf(__mode | ios_base::out) 404 { this->init(&_M_stringbuf); } 405 406 /** 407 * @brief Starts with an existing string buffer. 408 * @param str A string to copy as a starting buffer. 409 * @param mode Whether the buffer can read, or write, or both. 410 * 411 * @c ios_base::out is automatically included in @a mode. 412 * 413 * Initializes @c sb using @a str and @c mode|out, and passes @c &sb 414 * to the base class initializer. 415 * 416 * That's a lie. We initialize the base class with NULL, because the 417 * string class does its own memory management. 418 */ 419 explicit 420 basic_ostringstream(const __string_type& __str, 421 ios_base::openmode __mode = ios_base::out) 422 : __ostream_type(), _M_stringbuf(__str, __mode | ios_base::out) 423 { this->init(&_M_stringbuf); } 424 425 /** 426 * @brief The destructor does nothing. 427 * 428 * The buffer is deallocated by the stringbuf object, not the 429 * formatting stream. 430 */ 431 ~basic_ostringstream() 432 { } 433 434 // Members: 435 /** 436 * @brief Accessing the underlying buffer. 437 * @return The current basic_stringbuf buffer. 438 * 439 * This hides both signatures of std::basic_ios::rdbuf(). 440 */ 441 __stringbuf_type* 442 rdbuf() const 443 { return const_cast<__stringbuf_type*>(&_M_stringbuf); } 444 445 /** 446 * @brief Copying out the string buffer. 447 * @return @c rdbuf()->str() 448 */ 449 __string_type 450 str() const 451 { return _M_stringbuf.str(); } 452 453 /** 454 * @brief Setting a new buffer. 455 * @param s The string to use as a new sequence. 456 * 457 * Calls @c rdbuf()->str(s). 458 */ 459 void 460 str(const __string_type& __s) 461 { _M_stringbuf.str(__s); } 462 }; 463 464 465 // [27.7.4] Template class basic_stringstream 466 /** 467 * @brief Controlling input and output for std::string. 468 * @ingroup io 469 * 470 * This class supports reading from and writing to objects of type 471 * std::basic_string, using the inherited functions from 472 * std::basic_iostream. To control the associated sequence, an instance 473 * of std::basic_stringbuf is used, which this page refers to as @c sb. 474 */ 475 template <typename _CharT, typename _Traits, typename _Alloc> 476 class basic_stringstream : public basic_iostream<_CharT, _Traits> 477 { 478 public: 479 // Types: 480 typedef _CharT char_type; 481 typedef _Traits traits_type; 482 // _GLIBCXX_RESOLVE_LIB_DEFECTS 483 // 251. basic_stringbuf missing allocator_type 484 typedef _Alloc allocator_type; 485 typedef typename traits_type::int_type int_type; 486 typedef typename traits_type::pos_type pos_type; 487 typedef typename traits_type::off_type off_type; 488 489 // Non-standard Types: 490 typedef basic_string<_CharT, _Traits, _Alloc> __string_type; 491 typedef basic_stringbuf<_CharT, _Traits, _Alloc> __stringbuf_type; 492 typedef basic_iostream<char_type, traits_type> __iostream_type; 493 494 private: 495 __stringbuf_type _M_stringbuf; 496 497 public: 498 // Constructors/destructors 499 /** 500 * @brief Default constructor starts with an empty string buffer. 501 * @param mode Whether the buffer can read, or write, or both. 502 * 503 * Initializes @c sb using @c mode, and passes @c &sb to the base 504 * class initializer. Does not allocate any buffer. 505 * 506 * That's a lie. We initialize the base class with NULL, because the 507 * string class does its own memory management. 508 */ 509 explicit 510 basic_stringstream(ios_base::openmode __m = ios_base::out | ios_base::in) 511 : __iostream_type(), _M_stringbuf(__m) 512 { this->init(&_M_stringbuf); } 513 514 /** 515 * @brief Starts with an existing string buffer. 516 * @param str A string to copy as a starting buffer. 517 * @param mode Whether the buffer can read, or write, or both. 518 * 519 * Initializes @c sb using @a str and @c mode, and passes @c &sb 520 * to the base class initializer. 521 * 522 * That's a lie. We initialize the base class with NULL, because the 523 * string class does its own memory management. 524 */ 525 explicit 526 basic_stringstream(const __string_type& __str, 527 ios_base::openmode __m = ios_base::out | ios_base::in) 528 : __iostream_type(), _M_stringbuf(__str, __m) 529 { this->init(&_M_stringbuf); } 530 531 /** 532 * @brief The destructor does nothing. 533 * 534 * The buffer is deallocated by the stringbuf object, not the 535 * formatting stream. 536 */ 537 ~basic_stringstream() 538 { } 539 540 // Members: 541 /** 542 * @brief Accessing the underlying buffer. 543 * @return The current basic_stringbuf buffer. 544 * 545 * This hides both signatures of std::basic_ios::rdbuf(). 546 */ 547 __stringbuf_type* 548 rdbuf() const 549 { return const_cast<__stringbuf_type*>(&_M_stringbuf); } 550 551 /** 552 * @brief Copying out the string buffer. 553 * @return @c rdbuf()->str() 554 */ 555 __string_type 556 str() const 557 { return _M_stringbuf.str(); } 558 559 /** 560 * @brief Setting a new buffer. 561 * @param s The string to use as a new sequence. 562 * 563 * Calls @c rdbuf()->str(s). 564 */ 565 void 566 str(const __string_type& __s) 567 { _M_stringbuf.str(__s); } 568 }; 569 570_GLIBCXX_END_NAMESPACE 571 572#ifndef _GLIBCXX_EXPORT_TEMPLATE 573# include <bits/sstream.tcc> 574#endif 575 576#endif /* _GLIBCXX_SSTREAM */ 577