libstdc++-v3/include/bits/ostream.tcc

   1 // Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
   2 //
   3 // This file is part of the GNU ISO C++ Library.  This library is free
   4 // software; you can redistribute it and/or modify it under the
   5 // terms of the GNU General Public License as published by the
   6 // Free Software Foundation; either version 2, or (at your option)
   7 // any later version.
   8
   9 // This library is distributed in the hope that it will be useful,
  10 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 // GNU General Public License for more details.
  13
  14 // You should have received a copy of the GNU General Public License along
  15 // with this library; see the file COPYING.  If not, write to the Free
  16 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  17 // USA.
  18
  19 // As a special exception, you may use this file as part of a free software
  20 // library without restriction.  Specifically, if other files instantiate
  21 // templates or use macros or inline functions from this file, or you compile
  22 // this file and link it with other files to produce an executable, this
  23 // file does not by itself cause the resulting executable to be covered by
  24 // the GNU General Public License.  This exception does not however
  25 // invalidate any other reasons why the executable file might be covered by
  26 // the GNU General Public License.
  27
  28 //
  29 // ISO C++ 14882: 27.6.2  Output streams
  30 //
  31
  32 #include <bits/std_locale.h>
  33
  34 namespace std
  35 {
  36   template<typename _CharT, typename _Traits>
  37     basic_ostream<_CharT, _Traits>::sentry::
  38     sentry(basic_ostream<_CharT,_Traits>& __os)
  39     : _M_ok(__os.good()), _M_os(__os)
  40     {
  41       // XXX MT
  42       if (_M_ok && __os.tie())
  43         __os.tie()->flush();
  44     }
  45
  46   template<typename _CharT, typename _Traits>
  47     basic_ostream<_CharT, _Traits>&
  48     basic_ostream<_CharT, _Traits>::
  49     operator<<(__ostream_type& (*__pf)(__ostream_type&))
  50     {
  51       sentry __cerb(*this);
  52       if (__cerb)
  53         {
  54           try
  55             { __pf(*this); }
  56           catch(exception& __fail)
  57             {
  58               // 27.6.2.5.1 Common requirements.
  59               // Turn this on without causing an ios::failure to be thrown.
  60               this->setstate(ios_base::badbit);
  61               if ((this->exceptions() & ios_base::badbit) != 0)
  62                 __throw_exception_again;
  63             }
  64         }
  65       return *this;
  66     }
  67
  68   template<typename _CharT, typename _Traits>
  69     basic_ostream<_CharT, _Traits>&
  70     basic_ostream<_CharT, _Traits>::
  71     operator<<(__ios_type& (*__pf)(__ios_type&))
  72     {
  73       sentry __cerb(*this);
  74       if (__cerb)
  75         {
  76           try
  77             { __pf(*this); }
  78           catch(exception& __fail)
  79             {
  80               // 27.6.2.5.1 Common requirements.
  81               // Turn this on without causing an ios::failure to be thrown.
  82               this->setstate(ios_base::badbit);
  83               if ((this->exceptions() & ios_base::badbit) != 0)
  84                 __throw_exception_again;
  85             }
  86         }
  87       return *this;
  88     }
  89
  90   template<typename _CharT, typename _Traits>
  91     basic_ostream<_CharT, _Traits>&
  92     basic_ostream<_CharT, _Traits>::
  93     operator<<(ios_base& (*__pf)(ios_base&))
  94     {
  95       sentry __cerb(*this);
  96       if (__cerb)
  97         {
  98           try
  99             { __pf(*this); }
 100           catch(exception& __fail)
 101             {
 102               // 27.6.2.5.1 Common requirements.
 103               // Turn this on without causing an ios::failure to be thrown.
 104               this->setstate(ios_base::badbit);
 105               if ((this->exceptions() & ios_base::badbit) != 0)
 106                 __throw_exception_again;
 107             }
 108         }
 109       return *this;
 110     }
 111
 112   template<typename _CharT, typename _Traits>
 113     basic_ostream<_CharT, _Traits>&
 114     basic_ostream<_CharT, _Traits>::operator<<(bool __n)
 115     {
 116       sentry __cerb(*this);
 117       if (__cerb)
 118         {
 119           try
 120             {
 121               if (_M_fnumput->put(*this, *this, this->fill(), __n).failed())
 122                 this->setstate(ios_base::badbit);
 123             }
 124           catch(exception& __fail)
 125             {
 126               // 27.6.1.2.1 Common requirements.
 127               // Turn this on without causing an ios::failure to be thrown.
 128               this->setstate(ios_base::badbit);
 129               if ((this->exceptions() & ios_base::badbit) != 0)
 130                 __throw_exception_again;
 131             }
 132         }
 133       return *this;
 134     }
 135
 136   template<typename _CharT, typename _Traits>
 137     basic_ostream<_CharT, _Traits>&
 138     basic_ostream<_CharT, _Traits>::operator<<(long __n)
 139     {
 140       sentry __cerb(*this);
 141       if (__cerb)
 142         {
 143           try
 144             {
 145               bool __f;
 146               ios_base::fmtflags __fmt = this->flags() & ios_base::basefield;
 147               if (__fmt & ios_base::oct || __fmt & ios_base::hex)
 148                 __f = _M_fnumput->put(*this, *this, this->fill(),
 149                                      static_cast<unsigned long>(__n)).failed();
 150               else
 151                 __f = _M_fnumput->put(*this, *this, this->fill(), __n).failed();
 152
 153               if (__f)
 154                 this->setstate(ios_base::badbit);
 155             }
 156           catch(exception& __fail)
 157             {
 158               // 27.6.1.2.1 Common requirements.
 159               // Turn this on without causing an ios::failure to be thrown.
 160               this->setstate(ios_base::badbit);
 161               if ((this->exceptions() & ios_base::badbit) != 0)
 162                 __throw_exception_again;
 163             }
 164         }
 165       return *this;
 166     }
 167
 168   template<typename _CharT, typename _Traits>
 169     basic_ostream<_CharT, _Traits>&
 170     basic_ostream<_CharT, _Traits>::operator<<(unsigned long __n)
 171     {
 172       sentry __cerb(*this);
 173       if (__cerb)
 174         {
 175           try
 176             {
 177               if (_M_fnumput->put(*this, *this, this->fill(), __n).failed())
 178                 this->setstate(ios_base::badbit);
 179             }
 180           catch(exception& __fail)
 181             {
 182               // 27.6.1.2.1 Common requirements.
 183               // Turn this on without causing an ios::failure to be thrown.
 184               this->setstate(ios_base::badbit);
 185               if ((this->exceptions() & ios_base::badbit) != 0)
 186                 __throw_exception_again;
 187             }
 188         }
 189       return *this;
 190     }
 191
 192 #ifdef _GLIBCPP_USE_LONG_LONG
 193   template<typename _CharT, typename _Traits>
 194     basic_ostream<_CharT, _Traits>&
 195     basic_ostream<_CharT, _Traits>::operator<<(long long __n)
 196     {
 197       sentry __cerb(*this);
 198       if (__cerb)
 199         {
 200           try
 201             {
 202               bool __f;
 203               ios_base::fmtflags __fmt = this->flags() & ios_base::basefield;
 204               if (__fmt & ios_base::oct || __fmt & ios_base::hex)
 205                 __f = _M_fnumput->put(*this, *this, this->fill(),
 206                                 static_cast<unsigned long long>(__n)).failed();
 207               else
 208                 __f = _M_fnumput->put(*this, *this, this->fill(), __n).failed();
 209               if (__f)
 210                 this->setstate(ios_base::badbit);
 211             }
 212           catch(exception& __fail)
 213             {
 214               // 27.6.1.2.1 Common requirements.
 215               // Turn this on without causing an ios::failure to be thrown.
 216               this->setstate(ios_base::badbit);
 217               if ((this->exceptions() & ios_base::badbit) != 0)
 218                 __throw_exception_again;
 219             }
 220         }
 221       return *this;
 222     }
 223
 224   template<typename _CharT, typename _Traits>
 225     basic_ostream<_CharT, _Traits>&
 226     basic_ostream<_CharT, _Traits>::operator<<(unsigned long long __n)
 227     {
 228       sentry __cerb(*this);
 229       if (__cerb)
 230         {
 231           try
 232             {
 233               if (_M_fnumput->put(*this, *this, this->fill(), __n).failed())
 234                 this->setstate(ios_base::badbit);
 235             }
 236           catch(exception& __fail)
 237             {
 238               // 27.6.1.2.1 Common requirements.
 239               // Turn this on without causing an ios::failure to be thrown.
 240               this->setstate(ios_base::badbit);
 241               if ((this->exceptions() & ios_base::badbit) != 0)
 242                 __throw_exception_again;
 243             }
 244         }
 245       return *this;
 246     }
 247 #endif
 248
 249   template<typename _CharT, typename _Traits>
 250     basic_ostream<_CharT, _Traits>&
 251     basic_ostream<_CharT, _Traits>::operator<<(double __n)
 252     {
 253       sentry __cerb(*this);
 254       if (__cerb)
 255         {
 256           try
 257             {
 258               if (_M_fnumput->put(*this, *this, this->fill(), __n).failed())
 259                 this->setstate(ios_base::badbit);
 260             }
 261           catch(exception& __fail)
 262             {
 263               // 27.6.1.2.1 Common requirements.
 264               // Turn this on without causing an ios::failure to be thrown.
 265               this->setstate(ios_base::badbit);
 266               if ((this->exceptions() & ios_base::badbit) != 0)
 267                 __throw_exception_again;
 268             }
 269         }
 270       return *this;
 271     }
 272
 273   template<typename _CharT, typename _Traits>
 274     basic_ostream<_CharT, _Traits>&
 275     basic_ostream<_CharT, _Traits>::operator<<(long double __n)
 276     {
 277       sentry __cerb(*this);
 278       if (__cerb)
 279         {
 280           try
 281             {
 282               if (_M_fnumput->put(*this, *this, this->fill(), __n).failed())
 283                 this->setstate(ios_base::badbit);
 284             }
 285           catch(exception& __fail)
 286             {
 287               // 27.6.1.2.1 Common requirements.
 288               // Turn this on without causing an ios::failure to be thrown.
 289               this->setstate(ios_base::badbit);
 290               if ((this->exceptions() & ios_base::badbit) != 0)
 291                 __throw_exception_again;
 292             }
 293         }
 294       return *this;
 295     }
 296
 297   template<typename _CharT, typename _Traits>
 298     basic_ostream<_CharT, _Traits>&
 299     basic_ostream<_CharT, _Traits>::operator<<(const void* __n)
 300     {
 301       sentry __cerb(*this);
 302       if (__cerb)
 303         {
 304           try
 305             {
 306               if (_M_fnumput->put(*this, *this, this->fill(), __n).failed())
 307                 this->setstate(ios_base::badbit);
 308             }
 309           catch(exception& __fail)
 310             {
 311               // 27.6.1.2.1 Common requirements.
 312               // Turn this on without causing an ios::failure to be thrown.
 313               this->setstate(ios_base::badbit);
 314               if ((this->exceptions() & ios_base::badbit) != 0)
 315                 __throw_exception_again;
 316             }
 317         }
 318       return *this;
 319     }
 320
 321   template<typename _CharT, typename _Traits>
 322     basic_ostream<_CharT, _Traits>&
 323     basic_ostream<_CharT, _Traits>::operator<<(__streambuf_type* __sbin)
 324     {
 325       streamsize __xtrct = 0;
 326       __streambuf_type* __sbout = this->rdbuf();
 327       sentry __cerb(*this);
 328       if (__sbin && __cerb)
 329         __xtrct = __copy_streambufs(*this, __sbin, __sbout);
 330       if (!__sbin || !__xtrct)
 331         this->setstate(ios_base::failbit);
 332       return *this;
 333     }
 334
 335   template<typename _CharT, typename _Traits>
 336     basic_ostream<_CharT, _Traits>&
 337     basic_ostream<_CharT, _Traits>::put(char_type __c)
 338     {
 339       sentry __cerb(*this);
 340       if (__cerb)
 341         {
 342           int_type __put = rdbuf()->sputc(__c);
 343           if (__put != traits_type::to_int_type(__c))
 344             this->setstate(ios_base::badbit);
 345         }
 346       return *this;
 347     }
 348
 349   template<typename _CharT, typename _Traits>
 350     basic_ostream<_CharT, _Traits>&
 351     basic_ostream<_CharT, _Traits>::write(const _CharT* __s, streamsize __n)
 352     {
 353       sentry __cerb(*this);
 354       if (__cerb)
 355         {
 356           streamsize __put = this->rdbuf()->sputn(__s, __n);
 357           if ( __put != __n)
 358             this->setstate(ios_base::badbit);
 359         }
 360       return *this;
 361     }
 362
 363   template<typename _CharT, typename _Traits>
 364     basic_ostream<_CharT, _Traits>&
 365     basic_ostream<_CharT, _Traits>::flush()
 366     {
 367       sentry __cerb(*this);
 368       if (__cerb)
 369         {
 370           if (this->rdbuf() && this->rdbuf()->pubsync() == -1)
 371             this->setstate(ios_base::badbit);
 372         }
 373       return *this;
 374     }
 375
 376   template<typename _CharT, typename _Traits>
 377     typename basic_ostream<_CharT, _Traits>::pos_type
 378     basic_ostream<_CharT, _Traits>::tellp()
 379     {
 380       pos_type __ret = pos_type(-1);
 381       bool __testok = this->fail() != true;
 382
 383       if (__testok)
 384         __ret = this->rdbuf()->pubseekoff(0, ios_base::cur, ios_base::out);
 385       return __ret;
 386     }
 387
 388
 389   template<typename _CharT, typename _Traits>
 390     basic_ostream<_CharT, _Traits>&
 391     basic_ostream<_CharT, _Traits>::seekp(pos_type __pos)
 392     {
 393       bool __testok = this->fail() != true;
 394
 395       if (__testok)
 396 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
 397 // 136.  seekp, seekg setting wrong streams?
 398         this->rdbuf()->pubseekpos(__pos, ios_base::out);
 399 #endif
 400       return *this;
 401     }
 402
 403   template<typename _CharT, typename _Traits>
 404     basic_ostream<_CharT, _Traits>&
 405     basic_ostream<_CharT, _Traits>::
 406     seekp(off_type __off, ios_base::seekdir __d)
 407     {
 408       bool __testok = this->fail() != true;
 409
 410       if (__testok)
 411 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
 412 // 136.  seekp, seekg setting wrong streams?
 413         this->rdbuf()->pubseekoff(__off, __d, ios_base::out);
 414 #endif
 415       return *this;
 416     }
 417
 418   // 27.6.2.5.4 Character inserters
 419
 420   // Construct correctly padded string, as per 22.2.2.2.2
 421   // Similar in theory to __pad_numeric, from num_put, but it doesn't
 422   // use _S_fill: perhaps it should.
 423   // Assumes
 424   // __newlen > __oldlen
 425   // __news is allocated for __newlen size
 426   template<typename _CharT, typename _Traits>
 427     void
 428     __pad_char(basic_ios<_CharT, _Traits>& __ios,
 429                _CharT* __news, const _CharT* __olds,
 430                const streamsize __newlen, const streamsize __oldlen)
 431     {
 432       typedef _CharT    char_type;
 433       typedef _Traits   traits_type;
 434       typedef typename traits_type::int_type int_type;
 435
 436       int_type __plen = static_cast<size_t>(__newlen - __oldlen);
 437       char_type* __pads = static_cast<char_type*>(__builtin_alloca(sizeof(char_type) * __plen));
 438       traits_type::assign(__pads, __plen, __ios.fill());
 439
 440       char_type* __beg;
 441       char_type* __end;
 442       size_t __mod = 0;
 443       size_t __beglen; //either __plen or __oldlen
 444       ios_base::fmtflags __fmt = __ios.flags() & ios_base::adjustfield;
 445
 446       if (__fmt == ios_base::left)
 447         {
 448           // Padding last.
 449           __beg = const_cast<char_type*>(__olds);
 450           __beglen = __oldlen;
 451           __end = __pads;
 452         }
 453       else if (__fmt == ios_base::internal)
 454         {
 455           // Pad after the sign, if there is one.
 456           // Pad after 0[xX], if there is one.
 457           // Who came up with these rules, anyway? Jeeze.
 458           typedef _Format_cache<_CharT> __cache_type;
 459           __cache_type const* __fmt = __cache_type::_S_get(__ios);
 460           const char_type* __minus = traits_type::find(__olds, __oldlen,
 461                                                        __fmt->_S_minus);
 462           const char_type* __plus = traits_type::find(__olds, __oldlen,
 463                                                       __fmt->_S_plus);
 464           bool __testsign = __minus || __plus;
 465           bool __testhex = __olds[0] == '0'
 466                            && (__olds[1] == 'x' || __olds[1] == 'X');
 467
 468           if (__testhex)
 469             {
 470               __news[0] = __olds[0];
 471               __news[1] = __olds[1];
 472               __mod += 2;
 473               __beg = const_cast<char_type*>(__olds + __mod);
 474               __beglen = __oldlen - __mod;
 475               __end = __pads;
 476             }
 477           else if (__testsign)
 478             {
 479               __mod += __plen;
 480               const char_type* __sign = __minus ? __minus + 1: __plus + 1;
 481               __beg = const_cast<char_type*>(__olds);
 482               __beglen = __sign - __olds;
 483               __end = const_cast<char_type*>(__sign + __plen);
 484               traits_type::copy(__news + __beglen, __pads, __plen);
 485             }
 486           else
 487             {
 488               // Padding first.
 489               __beg = __pads;
 490               __beglen = __plen;
 491               __end = const_cast<char_type*>(__olds);
 492             }
 493         }
 494       else
 495         {
 496           // Padding first.
 497           __beg = __pads;
 498           __beglen = __plen;
 499           __end = const_cast<char_type*>(__olds);
 500         }
 501
 502       traits_type::copy(__news, __beg, __beglen);
 503       traits_type::copy(__news + __beglen, __end, __newlen - __beglen - __mod);
 504     }
 505
 506   template<typename _CharT, typename _Traits>
 507     basic_ostream<_CharT, _Traits>&
 508     operator<<(basic_ostream<_CharT, _Traits>& __out, _CharT __c)
 509     {
 510       typedef basic_ostream<_CharT, _Traits> __ostream_type;
 511       typename __ostream_type::sentry __cerb(__out);
 512       if (__cerb)
 513         {
 514           try
 515             {
 516               streamsize __w = __out.width();
 517               _CharT* __pads = static_cast<_CharT*>(__builtin_alloca(sizeof(_CharT) * __w));
 518               __pads[0] = __c;
 519               streamsize __len = 1;
 520               if (__w > __len)
 521                 {
 522                   __pad_char(__out, __pads, &__c, __w, __len);
 523                   __len = __w;
 524                 }
 525               __out.write(__pads, __len);
 526               __out.width(0);
 527             }
 528           catch(exception& __fail)
 529             {
 530               // 27.6.1.2.1 Common requirements.
 531               // Turn this on without causing an ios::failure to be thrown.
 532               __out.setstate(ios_base::badbit);
 533               if ((__out.exceptions() & ios_base::badbit) != 0)
 534                 __throw_exception_again;
 535             }
 536         }
 537       return __out;
 538     }
 539
 540   // Specialization
 541   template <class _Traits>
 542     basic_ostream<char, _Traits>&
 543     operator<<(basic_ostream<char, _Traits>& __out, char __c)
 544     {
 545       typedef basic_ostream<char, _Traits> __ostream_type;
 546       typename __ostream_type::sentry __cerb(__out);
 547       if (__cerb)
 548         {
 549           try
 550             {
 551               streamsize __w = __out.width();
 552               char* __pads = static_cast<char*>(__builtin_alloca(__w + 1));
 553               __pads[0] = __c;
 554               streamsize __len = 1;
 555               if (__w > __len)
 556                 {
 557                   __pad_char(__out, __pads, &__c, __w, __len);
 558                   __len = __w;
 559                 }
 560               __out.write(__pads, __len);
 561               __out.width(0);
 562             }
 563           catch(exception& __fail)
 564             {
 565               // 27.6.1.2.1 Common requirements.
 566               // Turn this on without causing an ios::failure to be thrown.
 567               __out.setstate(ios_base::badbit);
 568               if ((__out.exceptions() & ios_base::badbit) != 0)
 569                 __throw_exception_again;
 570             }
 571         }
 572       return __out;
 573      }
 574
 575   template<typename _CharT, typename _Traits>
 576     basic_ostream<_CharT, _Traits>&
 577     operator<<(basic_ostream<_CharT, _Traits>& __out, const _CharT* __s)
 578     {
 579       typedef basic_ostream<_CharT, _Traits> __ostream_type;
 580       typename __ostream_type::sentry __cerb(__out);
 581       if (__cerb)
 582         {
 583           try
 584             {
 585               streamsize __w = __out.width();
 586               _CharT* __pads = static_cast<_CharT*>(__builtin_alloca(sizeof(_CharT) * __w));
 587               streamsize __len = static_cast<streamsize>(_Traits::length(__s));
 588               if (__w > __len)
 589                 {
 590                   __pad_char(__out, __pads, __s, __w, __len);
 591                   __s = __pads;
 592                   __len = __w;
 593                 }
 594               __out.write(__s, __len);
 595               __out.width(0);
 596             }
 597           catch(exception& __fail)
 598             {
 599               // 27.6.1.2.1 Common requirements.
 600               // Turn this on without causing an ios::failure to be thrown.
 601               __out.setstate(ios_base::badbit);
 602               if ((__out.exceptions() & ios_base::badbit) != 0)
 603                 __throw_exception_again;
 604             }
 605         }
 606       return __out;
 607     }
 608
 609   template<typename _CharT, typename _Traits>
 610     basic_ostream<_CharT, _Traits>&
 611     operator<<(basic_ostream<_CharT, _Traits>& __out, const char* __s)
 612     {
 613       typedef basic_ostream<_CharT, _Traits> __ostream_type;
 614 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
 615 // 167.  Improper use of traits_type::length()
 616       typedef char_traits<char>              __ctraits_type;
 617 #endif
 618       typename __ostream_type::sentry __cerb(__out);
 619       if (__cerb)
 620         {
 621           size_t __clen = __ctraits_type::length(__s);
 622           _CharT* __ws = static_cast<_CharT*>(__builtin_alloca(sizeof(_CharT) * (__clen + 1)));
 623           for (size_t  __i = 0; __i <= __clen; ++__i)
 624             __ws[__i] = __out.widen(__s[__i]);
 625           _CharT* __str = __ws;
 626
 627           try
 628             {
 629               streamsize __len = static_cast<streamsize>(__clen);
 630               streamsize __w = __out.width();
 631               _CharT* __pads = static_cast<_CharT*>(__builtin_alloca(sizeof(_CharT) * __w));
 632
 633               if (__w > __len)
 634                 {
 635                   __pad_char(__out, __pads, __ws, __w, __len);
 636                   __str = __pads;
 637                   __len = __w;
 638                 }
 639               __out.write(__str, __len);
 640               __out.width(0);
 641             }
 642           catch(exception& __fail)
 643             {
 644               // 27.6.1.2.1 Common requirements.
 645               // Turn this on without causing an ios::failure to be thrown.
 646               __out.setstate(ios_base::badbit);
 647               if ((__out.exceptions() & ios_base::badbit) != 0)
 648                 __throw_exception_again;
 649             }
 650         }
 651       return __out;
 652     }
 653
 654   // Partial specializationss
 655   template<class _Traits>
 656     basic_ostream<char, _Traits>&
 657     operator<<(basic_ostream<char, _Traits>& __out, const char* __s)
 658     {
 659       typedef basic_ostream<char, _Traits> __ostream_type;
 660       typename __ostream_type::sentry __cerb(__out);
 661       if (__cerb)
 662         {
 663           try
 664             {
 665               streamsize __w = __out.width();
 666               char* __pads = static_cast<char*>(__builtin_alloca(__w));
 667               streamsize __len = static_cast<streamsize>(_Traits::length(__s));
 668               if (__w > __len)
 669                 {
 670                   __pad_char(__out, __pads, __s, __w, __len);
 671                   __s = __pads;
 672                   __len = __w;
 673                 }
 674               __out.write(__s, __len);
 675               __out.width(0);
 676             }
 677           catch(exception& __fail)
 678             {
 679               // 27.6.1.2.1 Common requirements.
 680               // Turn this on without causing an ios::failure to be thrown.
 681               __out.setstate(ios_base::badbit);
 682               if ((__out.exceptions() & ios_base::badbit) != 0)
 683                 __throw_exception_again;
 684             }
 685         }
 686       return __out;
 687     }
 688
 689   // 21.3.7.9 basic_string::operator<<
 690   template<typename _CharT, typename _Traits, typename _Alloc>
 691     basic_ostream<_CharT, _Traits>&
 692     operator<<(basic_ostream<_CharT, _Traits>& __out,
 693                const basic_string<_CharT, _Traits, _Alloc>& __str)
 694     {
 695       typedef basic_ostream<_CharT, _Traits> __ostream_type;
 696       typename __ostream_type::sentry __cerb(__out);
 697       if (__cerb)
 698         {
 699           const _CharT* __s = __str.data();
 700           streamsize __w = __out.width();
 701           _CharT* __pads = static_cast<_CharT*>(__builtin_alloca(sizeof(_CharT) * __w));
 702           streamsize __len = static_cast<streamsize>(__str.size());
 703 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
 704           // 25. String operator<< uses width() value wrong
 705 #endif
 706           if (__w > __len)
 707             {
 708               __pad_char(__out, __pads, __s, __w, __len);
 709               __s = __pads;
 710               __len = __w;
 711             }
 712           streamsize __res = __out.rdbuf()->sputn(__s, __len);
 713           __out.width(0);
 714           if (__res != __len)
 715             __out.setstate(ios_base::failbit);
 716         }
 717       return __out;
 718     }
 719 } // namespace std
 720
 721 // Local Variables:
 722 // mode:C++
 723 // End:
 724