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

   1 // File position object and stream types
   2
   3 // Copyright (C) 1997, 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 2, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // You should have received a copy of the GNU General Public License along
  17 // with this library; see the file COPYING.  If not, write to the Free
  18 // Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
  19 // USA.
  20
  21 // As a special exception, you may use this file as part of a free software
  22 // library without restriction.  Specifically, if other files instantiate
  23 // templates or use macros or inline functions from this file, or you compile
  24 // this file and link it with other files to produce an executable, this
  25 // file does not by itself cause the resulting executable to be covered by
  26 // the GNU General Public License.  This exception does not however
  27 // invalidate any other reasons why the executable file might be covered by
  28 // the GNU General Public License.
  29
  30 //
  31 // ISO C++ 14882: 27 Input/output library
  32 //
  33
  34 #ifndef _CPP_BITS_FPOS_H
  35 #define _CPP_BITS_FPOS_H 1
  36
  37 // Need this here as well as in std_ios because fpos is used in
  38 // char_traits, and char_traits is used by string, which may or may
  39 // not have included the std_ios file.
  40 #include <bits/c++io.h>
  41
  42 namespace std {
  43
  44   // 27.4.1  Types
  45
  46   // 27.4.3  Template class fpos
  47   template<typename _StateT>
  48     class fpos
  49     {
  50     public:
  51       // Types:
  52       typedef _StateT __state_type;
  53
  54     private:
  55       __state_type      _M_st;
  56       streamoff         _M_off;
  57
  58     public:
  59       __state_type
  60       state() const  { return _M_st; }
  61
  62       void
  63       state(__state_type __st)  { _M_st = __st; }
  64
  65       // NB: The standard defines only the implicit copy ctor and the
  66       // previous two members.  The rest is a "conforming extension".
  67       fpos(): _M_st(__state_type()), _M_off(streamoff()) { }
  68
  69       fpos(streamoff __off, __state_type __st = __state_type())
  70       : _M_st(__st), _M_off(__off) { }
  71
  72       operator streamoff() const { return _M_off; }
  73
  74       fpos&
  75       operator+=(streamoff __off) { _M_off += __off; return *this; }
  76
  77       fpos&
  78       operator-=(streamoff __off) { _M_off -= __off; return *this; }
  79
  80       bool
  81       operator==(const fpos& __pos) const { return _M_off == __pos._M_off; }
  82
  83       bool
  84       operator!=(const fpos& __pos) const { return _M_off != __pos._M_off; }
  85
  86       streamoff
  87       _M_position() const { return _M_off; }
  88
  89       void
  90       _M_position(streamoff __off)  { _M_off = __off; }
  91     };
  92
  93   template<typename _State>
  94     inline fpos<_State>
  95     operator+(const fpos<_State>& __pos, streamoff __off)
  96     {
  97       fpos<_State> t(__pos);
  98       return t += __off;
  99     }
 100
 101   template<typename _State>
 102     inline fpos<_State>
 103     operator-(const fpos<_State>& __pos, streamoff __off)
 104     {
 105       fpos<_State> t(__pos);
 106       return t -= __off;
 107     }
 108
 109   template<typename _State>
 110     inline streamoff
 111     operator-(const fpos<_State>& __pos1, const fpos<_State>& __pos2)
 112     { return __pos1._M_position() - __pos2._M_position(); }
 113
 114 }  // namespace std
 115
 116 #endif /* _CPP_BITS_FPOS_H */
 117
 118