std_streambuf.h revision 132720
1// Stream buffer classes -*- C++ -*- 2 3// Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004 4// 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 2, 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// You should have received a copy of the GNU General Public License along 18// with this library; see the file COPYING. If not, write to the Free 19// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, 20// USA. 21 22// As a special exception, you may use this file as part of a free software 23// library without restriction. Specifically, if other files instantiate 24// templates or use macros or inline functions from this file, or you compile 25// this file and link it with other files to produce an executable, this 26// file does not by itself cause the resulting executable to be covered by 27// the GNU General Public License. This exception does not however 28// invalidate any other reasons why the executable file might be covered by 29// the GNU General Public License. 30 31// 32// ISO C++ 14882: 27.5 Stream buffers 33// 34 35/** @file streambuf 36 * This is a Standard C++ Library header. You should @c #include this header 37 * in your programs, rather than any of the "st[dl]_*.h" implementation files. 38 */ 39 40#ifndef _CLIBXX_STREAMBUF 41#define _CLIBXX_STREAMBUF 1 42 43#pragma GCC system_header 44 45#include <bits/c++config.h> 46#include <iosfwd> 47#include <bits/localefwd.h> 48#include <bits/ios_base.h> 49 50namespace std 51{ 52 /** 53 * @if maint 54 * Does stuff. 55 * @endif 56 */ 57 template<typename _CharT, typename _Traits> 58 streamsize 59 __copy_streambufs(basic_streambuf<_CharT, _Traits>* __sbin, 60 basic_streambuf<_CharT, _Traits>* __sbout); 61 62 /** 63 * @brief The actual work of input and output (interface). 64 * 65 * This is a base class. Derived stream buffers each control a 66 * pair of character sequences: one for input, and one for output. 67 * 68 * Section [27.5.1] of the standard describes the requirements and 69 * behavior of stream buffer classes. That section (three paragraphs) 70 * is reproduced here, for simplicity and accuracy. 71 * 72 * -# Stream buffers can impose various constraints on the sequences 73 * they control. Some constraints are: 74 * - The controlled input sequence can be not readable. 75 * - The controlled output sequence can be not writable. 76 * - The controlled sequences can be associated with the contents of 77 * other representations for character sequences, such as external 78 * files. 79 * - The controlled sequences can support operations @e directly to or 80 * from associated sequences. 81 * - The controlled sequences can impose limitations on how the 82 * program can read characters from a sequence, write characters to 83 * a sequence, put characters back into an input sequence, or alter 84 * the stream position. 85 * . 86 * -# Each sequence is characterized by three pointers which, if non-null, 87 * all point into the same @c charT array object. The array object 88 * represents, at any moment, a (sub)sequence of characters from the 89 * sequence. Operations performed on a sequence alter the values 90 * stored in these pointers, perform reads and writes directly to or 91 * from associated sequences, and alter "the stream position" and 92 * conversion state as needed to maintain this subsequence relationship. 93 * The three pointers are: 94 * - the <em>beginning pointer</em>, or lowest element address in the 95 * array (called @e xbeg here); 96 * - the <em>next pointer</em>, or next element address that is a 97 * current candidate for reading or writing (called @e xnext here); 98 * - the <em>end pointer</em>, or first element address beyond the 99 * end of the array (called @e xend here). 100 * . 101 * -# The following semantic constraints shall always apply for any set 102 * of three pointers for a sequence, using the pointer names given 103 * immediately above: 104 * - If @e xnext is not a null pointer, then @e xbeg and @e xend shall 105 * also be non-null pointers into the same @c charT array, as 106 * described above; otherwise, @e xbeg and @e xend shall also be null. 107 * - If @e xnext is not a null pointer and @e xnext < @e xend for an 108 * output sequence, then a <em>write position</em> is available. 109 * In this case, @e *xnext shall be assignable as the next element 110 * to write (to put, or to store a character value, into the sequence). 111 * - If @e xnext is not a null pointer and @e xbeg < @e xnext for an 112 * input sequence, then a <em>putback position</em> is available. 113 * In this case, @e xnext[-1] shall have a defined value and is the 114 * next (preceding) element to store a character that is put back 115 * into the input sequence. 116 * - If @e xnext is not a null pointer and @e xnext< @e xend for an 117 * input sequence, then a <em>read position</em> is available. 118 * In this case, @e *xnext shall have a defined value and is the 119 * next element to read (to get, or to obtain a character value, 120 * from the sequence). 121 */ 122 template<typename _CharT, typename _Traits> 123 class basic_streambuf 124 { 125 public: 126 //@{ 127 /** 128 * These are standard types. They permit a standardized way of 129 * referring to names of (or names dependant on) the template 130 * parameters, which are specific to the implementation. 131 */ 132 typedef _CharT char_type; 133 typedef _Traits traits_type; 134 typedef typename traits_type::int_type int_type; 135 typedef typename traits_type::pos_type pos_type; 136 typedef typename traits_type::off_type off_type; 137 //@} 138 139 //@{ 140 /** 141 * @if maint 142 * This is a non-standard type. 143 * @endif 144 */ 145 typedef basic_streambuf<char_type, traits_type> __streambuf_type; 146 //@} 147 148 friend class basic_ios<char_type, traits_type>; 149 friend class basic_istream<char_type, traits_type>; 150 friend class basic_ostream<char_type, traits_type>; 151 friend class istreambuf_iterator<char_type, traits_type>; 152 friend class ostreambuf_iterator<char_type, traits_type>; 153 154 friend streamsize 155 __copy_streambufs<>(__streambuf_type* __sbin, 156 __streambuf_type* __sbout); 157 158 protected: 159 //@{ 160 /** 161 * @if maint 162 * This is based on _IO_FILE, just reordered to be more consistent, 163 * and is intended to be the most minimal abstraction for an 164 * internal buffer. 165 * - get == input == read 166 * - put == output == write 167 * @endif 168 */ 169 char_type* _M_in_beg; // Start of get area. 170 char_type* _M_in_cur; // Current read area. 171 char_type* _M_in_end; // End of get area. 172 char_type* _M_out_beg; // Start of put area. 173 char_type* _M_out_cur; // Current put area. 174 char_type* _M_out_end; // End of put area. 175 176 /** 177 * @if maint 178 * Current locale setting. 179 * @endif 180 */ 181 locale _M_buf_locale; 182 183 public: 184 /// Destructor deallocates no buffer space. 185 virtual 186 ~basic_streambuf() 187 { } 188 189 // [27.5.2.2.1] locales 190 /** 191 * @brief Entry point for imbue(). 192 * @param loc The new locale. 193 * @return The previous locale. 194 * 195 * Calls the derived imbue(loc). 196 */ 197 locale 198 pubimbue(const locale &__loc) 199 { 200 locale __tmp(this->getloc()); 201 this->imbue(__loc); 202 _M_buf_locale = __loc; 203 return __tmp; 204 } 205 206 /** 207 * @brief Locale access. 208 * @return The current locale in effect. 209 * 210 * If pubimbue(loc) has been called, then the most recent @c loc 211 * is returned. Otherwise the global locale in effect at the time 212 * of construction is returned. 213 */ 214 locale 215 getloc() const 216 { return _M_buf_locale; } 217 218 // [27.5.2.2.2] buffer management and positioning 219 //@{ 220 /** 221 * @brief Entry points for derived buffer functions. 222 * 223 * The public versions of @c pubfoo dispatch to the protected 224 * derived @c foo member functions, passing the arguments (if any) 225 * and returning the result unchanged. 226 */ 227 __streambuf_type* 228 pubsetbuf(char_type* __s, streamsize __n) 229 { return this->setbuf(__s, __n); } 230 231 pos_type 232 pubseekoff(off_type __off, ios_base::seekdir __way, 233 ios_base::openmode __mode = ios_base::in | ios_base::out) 234 { return this->seekoff(__off, __way, __mode); } 235 236 pos_type 237 pubseekpos(pos_type __sp, 238 ios_base::openmode __mode = ios_base::in | ios_base::out) 239 { return this->seekpos(__sp, __mode); } 240 241 int 242 pubsync() { return this->sync(); } 243 //@} 244 245 // [27.5.2.2.3] get area 246 /** 247 * @brief Looking ahead into the stream. 248 * @return The number of characters available. 249 * 250 * If a read position is available, returns the number of characters 251 * available for reading before the buffer must be refilled. 252 * Otherwise returns the derived @c showmanyc(). 253 */ 254 streamsize 255 in_avail() 256 { 257 const streamsize __ret = this->egptr() - this->gptr(); 258 return __ret ? __ret : this->showmanyc(); 259 } 260 261 /** 262 * @brief Getting the next character. 263 * @return The next character, or eof. 264 * 265 * Calls @c sbumpc(), and if that function returns 266 * @c traits::eof(), so does this function. Otherwise, @c sgetc(). 267 */ 268 int_type 269 snextc() 270 { 271 int_type __ret = traits_type::eof(); 272 if (__builtin_expect(!traits_type::eq_int_type(this->sbumpc(), 273 __ret), true)) 274 __ret = this->sgetc(); 275 return __ret; 276 } 277 278 /** 279 * @brief Getting the next character. 280 * @return The next character, or eof. 281 * 282 * If the input read position is available, returns that character 283 * and increments the read pointer, otherwise calls and returns 284 * @c uflow(). 285 */ 286 int_type 287 sbumpc() 288 { 289 int_type __ret; 290 if (__builtin_expect(this->gptr() < this->egptr(), true)) 291 { 292 __ret = traits_type::to_int_type(*this->gptr()); 293 this->gbump(1); 294 } 295 else 296 __ret = this->uflow(); 297 return __ret; 298 } 299 300 /** 301 * @brief Getting the next character. 302 * @return The next character, or eof. 303 * 304 * If the input read position is available, returns that character, 305 * otherwise calls and returns @c underflow(). Does not move the 306 * read position after fetching the character. 307 */ 308 int_type 309 sgetc() 310 { 311 int_type __ret; 312 if (__builtin_expect(this->gptr() < this->egptr(), true)) 313 __ret = traits_type::to_int_type(*this->gptr()); 314 else 315 __ret = this->underflow(); 316 return __ret; 317 } 318 319 /** 320 * @brief Entry point for xsgetn. 321 * @param s A buffer area. 322 * @param n A count. 323 * 324 * Returns xsgetn(s,n). The effect is to fill @a s[0] through 325 * @a s[n-1] with characters from the input sequence, if possible. 326 */ 327 streamsize 328 sgetn(char_type* __s, streamsize __n) 329 { return this->xsgetn(__s, __n); } 330 331 // [27.5.2.2.4] putback 332 /** 333 * @brief Pushing characters back into the input stream. 334 * @param c The character to push back. 335 * @return The previous character, if possible. 336 * 337 * Similar to sungetc(), but @a c is pushed onto the stream instead 338 * of "the previous character". If successful, the next character 339 * fetched from the input stream will be @a c. 340 */ 341 int_type 342 sputbackc(char_type __c) 343 { 344 int_type __ret; 345 const bool __testpos = this->eback() < this->gptr(); 346 if (__builtin_expect(!__testpos || 347 !traits_type::eq(__c, this->gptr()[-1]), false)) 348 __ret = this->pbackfail(traits_type::to_int_type(__c)); 349 else 350 { 351 this->gbump(-1); 352 __ret = traits_type::to_int_type(*this->gptr()); 353 } 354 return __ret; 355 } 356 357 /** 358 * @brief Moving backwards in the input stream. 359 * @return The previous character, if possible. 360 * 361 * If a putback position is available, this function decrements the 362 * input pointer and returns that character. Otherwise, calls and 363 * returns pbackfail(). The effect is to "unget" the last character 364 * "gotten". 365 */ 366 int_type 367 sungetc() 368 { 369 int_type __ret; 370 if (__builtin_expect(this->eback() < this->gptr(), true)) 371 { 372 this->gbump(-1); 373 __ret = traits_type::to_int_type(*this->gptr()); 374 } 375 else 376 __ret = this->pbackfail(); 377 return __ret; 378 } 379 380 // [27.5.2.2.5] put area 381 /** 382 * @brief Entry point for all single-character output functions. 383 * @param c A character to output. 384 * @return @a c, if possible. 385 * 386 * One of two public output functions. 387 * 388 * If a write position is available for the output sequence (i.e., 389 * the buffer is not full), stores @a c in that position, increments 390 * the position, and returns @c traits::to_int_type(c). If a write 391 * position is not available, returns @c overflow(c). 392 */ 393 int_type 394 sputc(char_type __c) 395 { 396 int_type __ret; 397 if (__builtin_expect(this->pptr() < this->epptr(), true)) 398 { 399 *this->pptr() = __c; 400 this->pbump(1); 401 __ret = traits_type::to_int_type(__c); 402 } 403 else 404 __ret = this->overflow(traits_type::to_int_type(__c)); 405 return __ret; 406 } 407 408 /** 409 * @brief Entry point for all single-character output functions. 410 * @param s A buffer read area. 411 * @param n A count. 412 * 413 * One of two public output functions. 414 * 415 * 416 * Returns xsputn(s,n). The effect is to write @a s[0] through 417 * @a s[n-1] to the output sequence, if possible. 418 */ 419 streamsize 420 sputn(const char_type* __s, streamsize __n) 421 { return this->xsputn(__s, __n); } 422 423 protected: 424 /** 425 * @brief Base constructor. 426 * 427 * Only called from derived constructors, and sets up all the 428 * buffer data to zero, including the pointers described in the 429 * basic_streambuf class description. Note that, as a result, 430 * - the class starts with no read nor write positions available, 431 * - this is not an error 432 */ 433 basic_streambuf() 434 : _M_in_beg(0), _M_in_cur(0), _M_in_end(0), 435 _M_out_beg(0), _M_out_cur(0), _M_out_end(0), 436 _M_buf_locale(locale()) 437 { } 438 439 // [27.5.2.3.1] get area access 440 //@{ 441 /** 442 * @brief Access to the get area. 443 * 444 * These functions are only available to other protected functions, 445 * including derived classes. 446 * 447 * - eback() returns the beginning pointer for the input sequence 448 * - gptr() returns the next pointer for the input sequence 449 * - egptr() returns the end pointer for the input sequence 450 */ 451 char_type* 452 eback() const { return _M_in_beg; } 453 454 char_type* 455 gptr() const { return _M_in_cur; } 456 457 char_type* 458 egptr() const { return _M_in_end; } 459 //@} 460 461 /** 462 * @brief Moving the read position. 463 * @param n The delta by which to move. 464 * 465 * This just advances the read position without returning any data. 466 */ 467 void 468 gbump(int __n) { _M_in_cur += __n; } 469 470 /** 471 * @brief Setting the three read area pointers. 472 * @param gbeg A pointer. 473 * @param gnext A pointer. 474 * @param gend A pointer. 475 * @post @a gbeg == @c eback(), @a gnext == @c gptr(), and 476 * @a gend == @c egptr() 477 */ 478 void 479 setg(char_type* __gbeg, char_type* __gnext, char_type* __gend) 480 { 481 _M_in_beg = __gbeg; 482 _M_in_cur = __gnext; 483 _M_in_end = __gend; 484 } 485 486 // [27.5.2.3.2] put area access 487 //@{ 488 /** 489 * @brief Access to the put area. 490 * 491 * These functions are only available to other protected functions, 492 * including derived classes. 493 * 494 * - pbase() returns the beginning pointer for the output sequence 495 * - pptr() returns the next pointer for the output sequence 496 * - epptr() returns the end pointer for the output sequence 497 */ 498 char_type* 499 pbase() const { return _M_out_beg; } 500 501 char_type* 502 pptr() const { return _M_out_cur; } 503 504 char_type* 505 epptr() const { return _M_out_end; } 506 //@} 507 508 /** 509 * @brief Moving the write position. 510 * @param n The delta by which to move. 511 * 512 * This just advances the write position without returning any data. 513 */ 514 void 515 pbump(int __n) { _M_out_cur += __n; } 516 517 /** 518 * @brief Setting the three write area pointers. 519 * @param pbeg A pointer. 520 * @param pend A pointer. 521 * @post @a pbeg == @c pbase(), @a pbeg == @c pptr(), and 522 * @a pend == @c epptr() 523 */ 524 void 525 setp(char_type* __pbeg, char_type* __pend) 526 { 527 _M_out_beg = _M_out_cur = __pbeg; 528 _M_out_end = __pend; 529 } 530 531 // [27.5.2.4] virtual functions 532 // [27.5.2.4.1] locales 533 /** 534 * @brief Changes translations. 535 * @param loc A new locale. 536 * 537 * Translations done during I/O which depend on the current locale 538 * are changed by this call. The standard adds, "Between invocations 539 * of this function a class derived from streambuf can safely cache 540 * results of calls to locale functions and to members of facets 541 * so obtained." 542 * 543 * @note Base class version does nothing. 544 */ 545 virtual void 546 imbue(const locale&) 547 { } 548 549 // [27.5.2.4.2] buffer management and positioning 550 /** 551 * @brief Maniuplates the buffer. 552 * 553 * Each derived class provides its own appropriate behavior. See 554 * the next-to-last paragraph of 555 * http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#2 for 556 * more on this function. 557 * 558 * @note Base class version does nothing, returns @c this. 559 */ 560 virtual basic_streambuf<char_type,_Traits>* 561 setbuf(char_type*, streamsize) 562 { return this; } 563 564 /** 565 * @brief Alters the stream positions. 566 * 567 * Each derived class provides its own appropriate behavior. 568 * @note Base class version does nothing, returns a @c pos_type 569 * that represents an invalid stream position. 570 */ 571 virtual pos_type 572 seekoff(off_type, ios_base::seekdir, 573 ios_base::openmode /*__mode*/ = ios_base::in | ios_base::out) 574 { return pos_type(off_type(-1)); } 575 576 /** 577 * @brief Alters the stream positions. 578 * 579 * Each derived class provides its own appropriate behavior. 580 * @note Base class version does nothing, returns a @c pos_type 581 * that represents an invalid stream position. 582 */ 583 virtual pos_type 584 seekpos(pos_type, 585 ios_base::openmode /*__mode*/ = ios_base::in | ios_base::out) 586 { return pos_type(off_type(-1)); } 587 588 /** 589 * @brief Synchronizes the buffer arrays with the controlled sequences. 590 * @return -1 on failure. 591 * 592 * Each derived class provides its own appropriate behavior, 593 * including the definition of "failure". 594 * @note Base class version does nothing, returns zero. 595 */ 596 virtual int 597 sync() { return 0; } 598 599 // [27.5.2.4.3] get area 600 /** 601 * @brief Investigating the data available. 602 * @return An estimate of the number of characters available in the 603 * input sequence, or -1. 604 * 605 * "If it returns a positive value, then successive calls to 606 * @c underflow() will not return @c traits::eof() until at least that 607 * number of characters have been supplied. If @c showmanyc() 608 * returns -1, then calls to @c underflow() or @c uflow() will fail." 609 * [27.5.2.4.3]/1 610 * 611 * @note Base class version does nothing, returns zero. 612 * @note The standard adds that "the intention is not only that the 613 * calls [to underflow or uflow] will not return @c eof() but 614 * that they will return "immediately". 615 * @note The standard adds that "the morphemes of @c showmanyc are 616 * "es-how-many-see", not "show-manic". 617 */ 618 virtual streamsize 619 showmanyc() { return 0; } 620 621 /** 622 * @brief Multiple character extraction. 623 * @param s A buffer area. 624 * @param n Maximum number of characters to assign. 625 * @return The number of characters assigned. 626 * 627 * Fills @a s[0] through @a s[n-1] with characters from the input 628 * sequence, as if by @c sbumpc(). Stops when either @a n characters 629 * have been copied, or when @c traits::eof() would be copied. 630 * 631 * It is expected that derived classes provide a more efficient 632 * implementation by overriding this definition. 633 */ 634 virtual streamsize 635 xsgetn(char_type* __s, streamsize __n); 636 637 /** 638 * @brief Fetches more data from the controlled sequence. 639 * @return The first character from the <em>pending sequence</em>. 640 * 641 * Informally, this function is called when the input buffer is 642 * exhausted (or does not exist, as buffering need not actually be 643 * done). If a buffer exists, it is "refilled". In either case, the 644 * next available character is returned, or @c traits::eof() to 645 * indicate a null pending sequence. 646 * 647 * For a formal definiton of the pending sequence, see a good text 648 * such as Langer & Kreft, or [27.5.2.4.3]/7-14. 649 * 650 * A functioning input streambuf can be created by overriding only 651 * this function (no buffer area will be used). For an example, see 652 * http://gcc.gnu.org/onlinedocs/libstdc++/27_io/howto.html#6 653 * 654 * @note Base class version does nothing, returns eof(). 655 */ 656 virtual int_type 657 underflow() 658 { return traits_type::eof(); } 659 660 /** 661 * @brief Fetches more data from the controlled sequence. 662 * @return The first character from the <em>pending sequence</em>. 663 * 664 * Informally, this function does the same thing as @c underflow(), 665 * and in fact is required to call that function. It also returns 666 * the new character, like @c underflow() does. However, this 667 * function also moves the read position forward by one. 668 */ 669 virtual int_type 670 uflow() 671 { 672 int_type __ret = traits_type::eof(); 673 const bool __testeof = traits_type::eq_int_type(this->underflow(), 674 __ret); 675 if (!__testeof) 676 { 677 __ret = traits_type::to_int_type(*this->gptr()); 678 this->gbump(1); 679 } 680 return __ret; 681 } 682 683 // [27.5.2.4.4] putback 684 /** 685 * @brief Tries to back up the input sequence. 686 * @param c The character to be inserted back into the sequence. 687 * @return eof() on failure, "some other value" on success 688 * @post The constraints of @c gptr(), @c eback(), and @c pptr() 689 * are the same as for @c underflow(). 690 * 691 * @note Base class version does nothing, returns eof(). 692 */ 693 virtual int_type 694 pbackfail(int_type /* __c */ = traits_type::eof()) 695 { return traits_type::eof(); } 696 697 // Put area: 698 /** 699 * @brief Multiple character insertion. 700 * @param s A buffer area. 701 * @param n Maximum number of characters to write. 702 * @return The number of characters written. 703 * 704 * Writes @a s[0] through @a s[n-1] to the output sequence, as if 705 * by @c sputc(). Stops when either @a n characters have been 706 * copied, or when @c sputc() would return @c traits::eof(). 707 * 708 * It is expected that derived classes provide a more efficient 709 * implementation by overriding this definition. 710 */ 711 virtual streamsize 712 xsputn(const char_type* __s, streamsize __n); 713 714 /** 715 * @brief Consumes data from the buffer; writes to the 716 * controlled sequence. 717 * @param c An additional character to consume. 718 * @return eof() to indicate failure, something else (usually 719 * @a c, or not_eof()) 720 * 721 * Informally, this function is called when the output buffer is full 722 * (or does not exist, as buffering need not actually be done). If a 723 * buffer exists, it is "consumed", with "some effect" on the 724 * controlled sequence. (Typically, the buffer is written out to the 725 * sequence verbatim.) In either case, the character @a c is also 726 * written out, if @a c is not @c eof(). 727 * 728 * For a formal definiton of this function, see a good text 729 * such as Langer & Kreft, or [27.5.2.4.5]/3-7. 730 * 731 * A functioning output streambuf can be created by overriding only 732 * this function (no buffer area will be used). 733 * 734 * @note Base class version does nothing, returns eof(). 735 */ 736 virtual int_type 737 overflow(int_type /* __c */ = traits_type::eof()) 738 { return traits_type::eof(); } 739 740#ifdef _GLIBCXX_DEPRECATED 741 // Annex D.6 742 public: 743 /** 744 * @brief Tosses a character. 745 * 746 * Advances the read pointer, ignoring the character that would have 747 * been read. 748 * 749 * See http://gcc.gnu.org/ml/libstdc++/2002-05/msg00168.html 750 * 751 * @note This function has been deprecated by the standard. You 752 * must define @c _GLIBCXX_DEPRECATED to make this visible; see 753 * c++config.h. 754 */ 755 void 756 stossc() 757 { 758 if (this->gptr() < this->egptr()) 759 this->gbump(1); 760 else 761 this->uflow(); 762 } 763#endif 764 765 private: 766 // _GLIBCXX_RESOLVE_LIB_DEFECTS 767 // Side effect of DR 50. 768 basic_streambuf(const __streambuf_type& __sb) 769 : _M_in_beg(__sb._M_in_beg), _M_in_cur(__sb._M_in_cur), 770 _M_in_end(__sb._M_in_end), _M_out_beg(__sb._M_out_beg), 771 _M_out_cur(__sb._M_out_cur), _M_out_end(__sb._M_out_cur), 772 _M_buf_locale(__sb._M_buf_locale) 773 { } 774 775 __streambuf_type& 776 operator=(const __streambuf_type&) { return *this; }; 777 }; 778} // namespace std 779 780#ifndef _GLIBCXX_EXPORT_TEMPLATE 781# include <bits/streambuf.tcc> 782#endif 783 784#endif /* _GLIBCXX_STREAMBUF */ 785