libstdc++-v3/testsuite/27_io/basic_istream/tellg/wchar_t/fstream.cc

   1 // Copyright (C) 2004-2019 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 3, 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 COPYING3.  If not see
  16 // <http://www.gnu.org/licenses/>.
  17
  18 // { dg-require-fileio "" }
  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 #include <istream>
  26 #include <sstream>
  27 #include <fstream>
  28 #include <testsuite_hooks.h>
  29
  30 // fstreams
  31 void test04(void)
  32 {
  33   typedef std::wistream::off_type off_type;
  34
  35   std::wistream::pos_type pos01, pos02, pos03, pos04, pos05, pos06;
  36   std::ios_base::iostate state01, state02;
  37   const char str_lit01[] = "wistream_seeks-1.txt";
  38   const char str_lit02[] = "wistream_seeks-2.txt";
  39   std::wifstream if01(str_lit01, std::ios_base::in | std::ios_base::out);
  40   std::wifstream if02(str_lit01, std::ios_base::in);
  41   std::wifstream if03(str_lit02, std::ios_base::out | std::ios_base::trunc);
  42   VERIFY( if01.good() );
  43   VERIFY( if02.good() );
  44   VERIFY( if03.good() );
  45
  46   std::wistream is01(if01.rdbuf());
  47   std::wistream is02(if02.rdbuf());
  48   std::wistream is03(if03.rdbuf());
  49
  50   // pos_type tellg()
  51   // in | out
  52   pos01 = is01.tellg();
  53   pos02 = is01.tellg();
  54   VERIFY( pos01 == pos02 );
  55
  56   // in
  57   pos03 = is02.tellg();
  58   pos04 = is02.tellg();
  59   VERIFY( pos03 == pos04 );
  60
  61   // out
  62   pos05 = is03.tellg();
  63   pos06 = is03.tellg();
  64   VERIFY( pos05 == pos06 );
  65
  66   // cur
  67   // NB: see library issues list 136. It's the v-3 interp that seekg
  68   // only sets the input buffer, or else istreams with buffers that
  69   // have _M_mode == ios_base::out will fail to have consistency
  70   // between seekg and tellg.
  71   state01 = is01.rdstate();
  72   is01.seekg(10, std::ios_base::cur);
  73   state02 = is01.rdstate();
  74   pos01 = is01.tellg();
  75   VERIFY( pos01 == pos02 + off_type(10) );
  76   VERIFY( state01 == state02 );
  77   pos02 = is01.tellg();
  78   VERIFY( pos02 == pos01 );
  79 }
  80
  81 int main()
  82 {
  83   test04();
  84   return 0;
  85 }