libstdc++-v3/include/bits/ios_base.h

   1 // Iostreams base classes -*- C++ -*-
   2
   3 // Copyright (C) 1997, 1998, 1999, 2000, 2001, 2002
   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: 27.8  File-based streams
  33 //
  34
  35 /** @file ios_base.h
  36  *  This is an internal header file, included by other library headers.
  37  *  You should not attempt to use it directly.
  38  */
  39
  40 #ifndef _CPP_BITS_IOSBASE_H
  41 #define _CPP_BITS_IOSBASE_H 1
  42
  43 #pragma GCC system_header
  44
  45 #include <bits/atomicity.h>
  46
  47 namespace std
  48 {
  49   // The following definitions of bitmask types are enums, not ints,
  50   // as permitted (but not required) in the standard, in order to provide
  51   // better type safety in iostream calls.  A side effect is that
  52   // expressions involving them are no longer compile-time constants.
  53   enum _Ios_Fmtflags { _M_ios_fmtflags_end = 1L << 16 };
  54
  55   inline _Ios_Fmtflags
  56   operator&(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
  57   { return _Ios_Fmtflags(static_cast<int>(__a) & static_cast<int>(__b)); }
  58
  59   inline _Ios_Fmtflags
  60   operator|(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
  61   { return _Ios_Fmtflags(static_cast<int>(__a) | static_cast<int>(__b)); }
  62
  63   inline _Ios_Fmtflags
  64   operator^(_Ios_Fmtflags __a, _Ios_Fmtflags __b)
  65   { return _Ios_Fmtflags(static_cast<int>(__a) ^ static_cast<int>(__b)); }
  66
  67   inline _Ios_Fmtflags
  68   operator|=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
  69   { return __a = __a | __b; }
  70
  71   inline _Ios_Fmtflags
  72   operator&=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
  73   { return __a = __a & __b; }
  74
  75   inline _Ios_Fmtflags
  76   operator^=(_Ios_Fmtflags& __a, _Ios_Fmtflags __b)
  77   { return __a = __a ^ __b; }
  78
  79   inline _Ios_Fmtflags
  80   operator~(_Ios_Fmtflags __a)
  81   { return _Ios_Fmtflags(~static_cast<int>(__a)); }
  82
  83
  84   enum _Ios_Openmode { _M_ios_openmode_end = 1L << 16 };
  85
  86   inline _Ios_Openmode
  87   operator&(_Ios_Openmode __a, _Ios_Openmode __b)
  88   { return _Ios_Openmode(static_cast<int>(__a) & static_cast<int>(__b)); }
  89
  90   inline _Ios_Openmode
  91   operator|(_Ios_Openmode __a, _Ios_Openmode __b)
  92   { return _Ios_Openmode(static_cast<int>(__a) | static_cast<int>(__b)); }
  93
  94   inline _Ios_Openmode
  95   operator^(_Ios_Openmode __a, _Ios_Openmode __b)
  96   { return _Ios_Openmode(static_cast<int>(__a) ^ static_cast<int>(__b)); }
  97
  98   inline _Ios_Openmode
  99   operator|=(_Ios_Openmode& __a, _Ios_Openmode __b)
 100   { return __a = __a | __b; }
 101
 102   inline _Ios_Openmode
 103   operator&=(_Ios_Openmode& __a, _Ios_Openmode __b)
 104   { return __a = __a & __b; }
 105
 106   inline _Ios_Openmode
 107   operator^=(_Ios_Openmode& __a, _Ios_Openmode __b)
 108   { return __a = __a ^ __b; }
 109
 110   inline _Ios_Openmode
 111   operator~(_Ios_Openmode __a)
 112   { return _Ios_Openmode(~static_cast<int>(__a)); }
 113
 114
 115   enum _Ios_Iostate { _M_ios_iostate_end = 1L << 16 };
 116
 117   inline _Ios_Iostate
 118   operator&(_Ios_Iostate __a, _Ios_Iostate __b)
 119   { return _Ios_Iostate(static_cast<int>(__a) & static_cast<int>(__b)); }
 120
 121   inline _Ios_Iostate
 122   operator|(_Ios_Iostate __a, _Ios_Iostate __b)
 123   { return _Ios_Iostate(static_cast<int>(__a) | static_cast<int>(__b)); }
 124
 125   inline _Ios_Iostate
 126   operator^(_Ios_Iostate __a, _Ios_Iostate __b)
 127   { return _Ios_Iostate(static_cast<int>(__a) ^ static_cast<int>(__b)); }
 128
 129   inline _Ios_Iostate
 130   operator|=(_Ios_Iostate& __a, _Ios_Iostate __b)
 131   { return __a = __a | __b; }
 132
 133   inline _Ios_Iostate
 134   operator&=(_Ios_Iostate& __a, _Ios_Iostate __b)
 135   { return __a = __a & __b; }
 136
 137   inline _Ios_Iostate
 138   operator^=(_Ios_Iostate& __a, _Ios_Iostate __b)
 139   { return __a = __a ^ __b; }
 140
 141   inline _Ios_Iostate
 142   operator~(_Ios_Iostate __a)
 143   { return _Ios_Iostate(~static_cast<int>(__a)); }
 144
 145   enum _Ios_Seekdir { _M_ios_seekdir_end = 1L << 16 };
 146
 147   // 27.4.2  Class ios_base
 148   class ios_base
 149   {
 150   public:
 151
 152     // 27.4.2.1.1  Class ios_base::failure
 153     class failure : public exception
 154     {
 155     public:
 156 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
 157       //48.  Use of non-existent exception constructor
 158       explicit
 159       failure(const string& __str) throw();
 160
 161       // This declaration is not useless:
 162       // http://gcc.gnu.org/onlinedocs/gcc-3.0.2/gcc_6.html#SEC118
 163       virtual
 164       ~failure() throw();
 165
 166       virtual const char*
 167       what() const throw();
 168
 169     private:
 170       enum { _M_bufsize = 256 };
 171       char _M_name[_M_bufsize];
 172 #endif
 173     };
 174
 175     // 27.4.2.1.2  Type ios_base::fmtflags
 176     typedef _Ios_Fmtflags fmtflags;
 177     // 27.4.2.1.2  Type fmtflags
 178     static const fmtflags boolalpha =   fmtflags(__ios_flags::_S_boolalpha);
 179     static const fmtflags dec =         fmtflags(__ios_flags::_S_dec);
 180     static const fmtflags fixed =       fmtflags(__ios_flags::_S_fixed);
 181     static const fmtflags hex =         fmtflags(__ios_flags::_S_hex);
 182     static const fmtflags internal =    fmtflags(__ios_flags::_S_internal);
 183     static const fmtflags left =        fmtflags(__ios_flags::_S_left);
 184     static const fmtflags oct =         fmtflags(__ios_flags::_S_oct);
 185     static const fmtflags right =       fmtflags(__ios_flags::_S_right);
 186     static const fmtflags scientific =  fmtflags(__ios_flags::_S_scientific);
 187     static const fmtflags showbase =    fmtflags(__ios_flags::_S_showbase);
 188     static const fmtflags showpoint =   fmtflags(__ios_flags::_S_showpoint);
 189     static const fmtflags showpos =     fmtflags(__ios_flags::_S_showpos);
 190     static const fmtflags skipws =      fmtflags(__ios_flags::_S_skipws);
 191     static const fmtflags unitbuf =     fmtflags(__ios_flags::_S_unitbuf);
 192     static const fmtflags uppercase =   fmtflags(__ios_flags::_S_uppercase);
 193     static const fmtflags adjustfield = fmtflags(__ios_flags::_S_adjustfield);
 194     static const fmtflags basefield =   fmtflags(__ios_flags::_S_basefield);
 195     static const fmtflags floatfield =  fmtflags(__ios_flags::_S_floatfield);
 196
 197     // 27.4.2.1.3  Type ios_base::iostate
 198     typedef _Ios_Iostate iostate;
 199     static const iostate badbit =       iostate(__ios_flags::_S_badbit);
 200     static const iostate eofbit =       iostate(__ios_flags::_S_eofbit);
 201     static const iostate failbit =      iostate(__ios_flags::_S_failbit);
 202     static const iostate goodbit =      iostate(0);
 203
 204     // 27.4.2.1.4  Type openmode
 205     typedef _Ios_Openmode openmode;
 206     static const openmode app =         openmode(__ios_flags::_S_app);
 207     static const openmode ate =         openmode(__ios_flags::_S_ate);
 208     static const openmode binary =      openmode(__ios_flags::_S_bin);
 209     static const openmode in =          openmode(__ios_flags::_S_in);
 210     static const openmode out =         openmode(__ios_flags::_S_out);
 211     static const openmode trunc =       openmode(__ios_flags::_S_trunc);
 212
 213     // 27.4.2.1.5  Type seekdir
 214     typedef _Ios_Seekdir seekdir;
 215     static const seekdir beg =          seekdir(0);
 216     static const seekdir cur =          seekdir(SEEK_CUR);
 217     static const seekdir end =          seekdir(SEEK_END);
 218
 219 #ifdef _GLIBCPP_DEPRECATED
 220     typedef int io_state;
 221     typedef int open_mode;
 222     typedef int seek_dir;
 223 #endif
 224
 225     // Callbacks;
 226     enum event
 227     {
 228       erase_event,
 229       imbue_event,
 230       copyfmt_event
 231     };
 232
 233     typedef void (*event_callback) (event, ios_base&, int);
 234
 235     void
 236     register_callback(event_callback __fn, int __index);
 237
 238   protected:
 239     // Data Members
 240     streamsize          _M_precision;
 241     streamsize          _M_width;
 242     fmtflags            _M_flags;
 243     iostate             _M_exception;
 244     iostate             _M_streambuf_state;
 245
 246     // 27.4.2.6  Members for callbacks
 247     // 27.4.2.6  ios_base callbacks
 248     struct _Callback_list
 249     {
 250       // Data Members
 251       _Callback_list*           _M_next;
 252       ios_base::event_callback  _M_fn;
 253       int                       _M_index;
 254       _Atomic_word              _M_refcount;  // 0 means one reference.
 255
 256       _Callback_list(ios_base::event_callback __fn, int __index,
 257                      _Callback_list* __cb)
 258       : _M_next(__cb), _M_fn(__fn), _M_index(__index), _M_refcount(0) { }
 259
 260       void
 261       _M_add_reference() { __atomic_add(&_M_refcount, 1); }
 262
 263       // 0 => OK to delete.
 264       int
 265       _M_remove_reference() { return __exchange_and_add(&_M_refcount, -1); }
 266     };
 267
 268      _Callback_list*    _M_callbacks;
 269
 270     void
 271     _M_call_callbacks(event __ev) throw();
 272
 273     void
 274     _M_dispose_callbacks(void);
 275
 276     // 27.4.2.5  Members for iword/pword storage
 277     struct _Words
 278     {
 279       void*     _M_pword;
 280       long      _M_iword;
 281       _Words() : _M_pword(0), _M_iword(0) { }
 282     };
 283
 284     // Only for failed iword/pword calls.
 285     _Words              _M_word_zero;
 286
 287     // Guaranteed storage.
 288     static const int    _S_local_word_size = 8;
 289     _Words              _M_local_word[_S_local_word_size];
 290
 291     // Allocated storage.
 292     int                 _M_word_size;
 293     _Words*             _M_word;
 294
 295     _Words&
 296     _M_grow_words(int __index);
 297
 298     // Members for locale and locale caching.
 299     locale              _M_ios_locale;
 300
 301     void
 302     _M_init();
 303
 304   public:
 305
 306     // 27.4.2.1.6  Class ios_base::Init
 307     // Used to initialize standard streams. In theory, g++ could use
 308     // -finit-priority to order this stuff correctly without going
 309     // through these machinations.
 310     class Init
 311     {
 312       friend class ios_base;
 313     public:
 314       Init();
 315       ~Init();
 316
 317       static void
 318       _S_ios_create(bool __sync);
 319
 320       static void
 321       _S_ios_destroy();
 322
 323     private:
 324       static int        _S_ios_base_init;
 325       static bool       _S_synced_with_stdio;
 326     };
 327
 328     // Fmtflags state:
 329     inline fmtflags
 330     flags() const { return _M_flags; }
 331
 332     inline fmtflags
 333     flags(fmtflags __fmtfl)
 334     {
 335       fmtflags __old = _M_flags;
 336       _M_flags = __fmtfl;
 337       return __old;
 338     }
 339
 340     inline fmtflags
 341     setf(fmtflags __fmtfl)
 342     {
 343       fmtflags __old = _M_flags;
 344       _M_flags |= __fmtfl;
 345       return __old;
 346     }
 347
 348     inline fmtflags
 349     setf(fmtflags __fmtfl, fmtflags __mask)
 350     {
 351       fmtflags __old = _M_flags;
 352       _M_flags &= ~__mask;
 353       _M_flags |= (__fmtfl & __mask);
 354       return __old;
 355     }
 356
 357     inline void
 358     unsetf(fmtflags __mask) { _M_flags &= ~__mask; }
 359
 360     inline streamsize
 361     precision() const { return _M_precision; }
 362
 363     inline streamsize
 364     precision(streamsize __prec)
 365     {
 366       streamsize __old = _M_precision;
 367       _M_precision = __prec;
 368       return __old;
 369     }
 370
 371     inline streamsize
 372     width() const { return _M_width; }
 373
 374     inline streamsize
 375     width(streamsize __wide)
 376     {
 377       streamsize __old = _M_width;
 378       _M_width = __wide;
 379       return __old;
 380     }
 381
 382     static bool
 383     sync_with_stdio(bool __sync = true);
 384
 385     // Locales:
 386     locale
 387     imbue(const locale& __loc);
 388
 389     inline locale
 390     getloc() const { return _M_ios_locale; }
 391
 392     // Storage:
 393     static int
 394     xalloc() throw();
 395
 396     inline long&
 397     iword(int __ix)
 398     {
 399       _Words& __word = (__ix < _M_word_size)
 400                         ? _M_word[__ix] : _M_grow_words(__ix);
 401       return __word._M_iword;
 402     }
 403
 404     inline void*&
 405     pword(int __ix)
 406     {
 407       _Words& __word = (__ix < _M_word_size)
 408                         ? _M_word[__ix] : _M_grow_words(__ix);
 409       return __word._M_pword;
 410     }
 411
 412     // Destructor
 413     ~ios_base();
 414
 415   protected:
 416     ios_base();
 417
 418 #ifdef _GLIBCPP_RESOLVE_LIB_DEFECTS
 419   //50.  Copy constructor and assignment operator of ios_base
 420   private:
 421     ios_base(const ios_base&);
 422
 423     ios_base&
 424     operator=(const ios_base&);
 425 #endif
 426   };
 427
 428   // 27.4.5.1 fmtflags manipulators:
 429   inline ios_base&
 430   boolalpha(ios_base& __base)
 431   {
 432     __base.setf(ios_base::boolalpha);
 433     return __base;
 434   }
 435
 436   inline ios_base&
 437   noboolalpha(ios_base& __base)
 438   {
 439     __base.unsetf(ios_base::boolalpha);
 440     return __base;
 441   }
 442
 443   inline ios_base&
 444   showbase(ios_base& __base)
 445   {
 446     __base.setf(ios_base::showbase);
 447     return __base;
 448   }
 449
 450   inline ios_base&
 451   noshowbase(ios_base& __base)
 452   {
 453     __base.unsetf(ios_base::showbase);
 454     return __base;
 455   }
 456
 457   inline ios_base&
 458   showpoint(ios_base& __base)
 459   {
 460     __base.setf(ios_base::showpoint);
 461     return __base;
 462   }
 463
 464   inline ios_base&
 465   noshowpoint(ios_base& __base)
 466   {
 467     __base.unsetf(ios_base::showpoint);
 468     return __base;
 469   }
 470
 471   inline ios_base&
 472   showpos(ios_base& __base)
 473   {
 474     __base.setf(ios_base::showpos);
 475     return __base;
 476   }
 477
 478   inline ios_base&
 479   noshowpos(ios_base& __base)
 480   {
 481     __base.unsetf(ios_base::showpos);
 482     return __base;
 483   }
 484
 485   inline ios_base&
 486   skipws(ios_base& __base)
 487   {
 488     __base.setf(ios_base::skipws);
 489     return __base;
 490   }
 491
 492   inline ios_base&
 493   noskipws(ios_base& __base)
 494   {
 495     __base.unsetf(ios_base::skipws);
 496     return __base;
 497   }
 498
 499   inline ios_base&
 500   uppercase(ios_base& __base)
 501   {
 502     __base.setf(ios_base::uppercase);
 503     return __base;
 504   }
 505
 506   inline ios_base&
 507   nouppercase(ios_base& __base)
 508   {
 509     __base.unsetf(ios_base::uppercase);
 510     return __base;
 511   }
 512
 513   inline ios_base&
 514   unitbuf(ios_base& __base)
 515   {
 516      __base.setf(ios_base::unitbuf);
 517      return __base;
 518   }
 519
 520   inline ios_base&
 521   nounitbuf(ios_base& __base)
 522   {
 523      __base.unsetf(ios_base::unitbuf);
 524      return __base;
 525   }
 526
 527   // 27.4.5.2 adjustfield anipulators:
 528   inline ios_base&
 529   internal(ios_base& __base)
 530   {
 531      __base.setf(ios_base::internal, ios_base::adjustfield);
 532      return __base;
 533   }
 534
 535   inline ios_base&
 536   left(ios_base& __base)
 537   {
 538     __base.setf(ios_base::left, ios_base::adjustfield);
 539     return __base;
 540   }
 541
 542   inline ios_base&
 543   right(ios_base& __base)
 544   {
 545     __base.setf(ios_base::right, ios_base::adjustfield);
 546     return __base;
 547   }
 548
 549   // 27.4.5.3 basefield anipulators:
 550   inline ios_base&
 551   dec(ios_base& __base)
 552   {
 553     __base.setf(ios_base::dec, ios_base::basefield);
 554     return __base;
 555   }
 556
 557   inline ios_base&
 558   hex(ios_base& __base)
 559   {
 560     __base.setf(ios_base::hex, ios_base::basefield);
 561     return __base;
 562   }
 563
 564   inline ios_base&
 565   oct(ios_base& __base)
 566   {
 567     __base.setf(ios_base::oct, ios_base::basefield);
 568     return __base;
 569   }
 570
 571   // 27.4.5.4 floatfield anipulators:
 572   inline ios_base&
 573   fixed(ios_base& __base)
 574   {
 575     __base.setf(ios_base::fixed, ios_base::floatfield);
 576     return __base;
 577   }
 578
 579   inline ios_base&
 580   scientific(ios_base& __base)
 581   {
 582     __base.setf(ios_base::scientific, ios_base::floatfield);
 583     return __base;
 584   }
 585
 586 } // namespace std
 587
 588 #endif /* _CPP_BITS_IOSBASE_H */
 589