libstdc++-v3/testsuite/27_io/basic_istream/seekg/char/fstream.cc

   1 // 2000-06-29 bkoz
   2
   3 // Copyright (C) 2000-2020 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 3, 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 COPYING3.  If not see
  18 // <http://www.gnu.org/licenses/>.
  19
  20 // 27.6.1.3 unformatted input functions
  21 // NB: ostream has a particular "seeks" category. Adopt this for istreams too.
  22 // @require@ %-*.tst %-*.txt
  23 // @diff@ %-*.tst %-*.txt
  24
  25 // { dg-require-fileio "" }
  26
  27 #include <istream>
  28 #include <sstream>
  29 #include <fstream>
  30 #include <testsuite_hooks.h>
  31
  32 // fstreams
  33 void test04(void)
  34 {
  35   typedef std::istream::off_type off_type;
  36
  37   std::istream::pos_type pos01, pos02, pos03, pos04, pos05, pos06;
  38   std::ios_base::iostate state01, state02;
  39   const char str_lit01[] = "istream_seeks-1.txt";
  40   const char str_lit02[] = "istream_seeks-2.txt";
  41   std::ifstream if01(str_lit01, std::ios_base::in | std::ios_base::out);
  42   std::ifstream if02(str_lit01, std::ios_base::in);
  43   std::ifstream if03(str_lit02, std::ios_base::out | std::ios_base::trunc);
  44   VERIFY( if01.good() );
  45   VERIFY( if02.good() );
  46   VERIFY( if03.good() );
  47
  48   std::istream is01(if01.rdbuf());
  49   std::istream is02(if02.rdbuf());
  50   std::istream is03(if03.rdbuf());
  51
  52   pos01 = is01.tellg();
  53   pos02 = is01.tellg();
  54   pos03 = is02.tellg();
  55   pos04 = is02.tellg();
  56   pos05 = is03.tellg();
  57   pos06 = is03.tellg();
  58
  59   // istream& seekg(pos_type)
  60   // istream& seekg(off_type, ios_base::seekdir)
  61
  62   // cur
  63   // NB: see library issues list 136. It's the v-3 interp that seekg
  64   // only sets the input buffer, or else istreams with buffers that
  65   // have _M_mode == ios_base::out will fail to have consistency
  66   // between seekg and tellg.
  67   state01 = is01.rdstate();
  68   is01.seekg(10, std::ios_base::cur);
  69   state02 = is01.rdstate();
  70   pos01 = is01.tellg();
  71   VERIFY( pos01 == pos02 + off_type(10) );
  72   VERIFY( state01 == state02 );
  73   pos02 = is01.tellg();
  74   VERIFY( pos02 == pos01 );
  75
  76   state01 = is02.rdstate();
  77   is02.seekg(10, std::ios_base::cur);
  78   state02 = is02.rdstate();
  79   pos03 = is02.tellg();
  80   VERIFY( pos03 == pos04 + off_type(10) );
  81   VERIFY( state01 == state02 );
  82   pos04 = is02.tellg();
  83   VERIFY( pos03 == pos04 );
  84
  85   state01 = is03.rdstate();
  86   is03.seekg(10, std::ios_base::cur);
  87   state02 = is03.rdstate();
  88   pos05 = is03.tellg();
  89   VERIFY( pos05 == pos06 + off_type(10) );
  90   VERIFY( state01 == state02 );
  91   pos06 = is03.tellg();
  92   VERIFY( pos05 == pos06 );
  93
  94   // beg
  95   state01 = is01.rdstate();
  96   is01.seekg(20, std::ios_base::beg);
  97   state02 = is01.rdstate();
  98   pos01 = is01.tellg();
  99   VERIFY( pos01 == pos02 + off_type(10) );
 100   VERIFY( state01 == state02 );
 101   pos02 = is01.tellg();
 102   VERIFY( pos02 == pos01 );
 103
 104   state01 = is02.rdstate();
 105   is02.seekg(20, std::ios_base::beg);
 106   state02 = is02.rdstate();
 107   pos03 = is02.tellg();
 108   VERIFY( pos03 == pos04 + off_type(10) );
 109   VERIFY( state01 == state02 );
 110   pos04 = is02.tellg();
 111   VERIFY( pos03 == pos04 );
 112
 113   state01 = is03.rdstate();
 114   is03.seekg(20, std::ios_base::beg);
 115   state02 = is03.rdstate();
 116   pos05 = is03.tellg();
 117   VERIFY( pos05 == pos06 + off_type(10) );
 118   VERIFY( state01 == state02 );
 119   pos06 = is03.tellg();
 120   VERIFY( pos05 == pos06 );
 121 }
 122
 123 int main()
 124 {
 125   test04();
 126   return 0;
 127 }