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

   1 // 2000-06-29 bkoz
   2
   3 // Copyright (C) 2000-2016 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   bool test __attribute__((unused)) = true;
  38   std::istream::pos_type pos01, pos02, pos03, pos04, pos05, pos06;
  39   std::ios_base::iostate state01, state02;
  40   const char str_lit01[] = "istream_seeks-1.txt";
  41   const char str_lit02[] = "istream_seeks-2.txt";
  42   std::ifstream if01(str_lit01, std::ios_base::in | std::ios_base::out);
  43   std::ifstream if02(str_lit01, std::ios_base::in);
  44   std::ifstream if03(str_lit02, std::ios_base::out | std::ios_base::trunc);
  45   VERIFY( if01.good() );
  46   VERIFY( if02.good() );
  47   VERIFY( if03.good() );
  48
  49   std::istream is01(if01.rdbuf());
  50   std::istream is02(if02.rdbuf());
  51   std::istream is03(if03.rdbuf());
  52
  53   // pos_type tellg()
  54   // in | out
  55   pos01 = is01.tellg();
  56   pos02 = is01.tellg();
  57   VERIFY( pos01 == pos02 );
  58
  59   // in
  60   pos03 = is02.tellg();
  61   pos04 = is02.tellg();
  62   VERIFY( pos03 == pos04 );
  63
  64   // out
  65   pos05 = is03.tellg();
  66   pos06 = is03.tellg();
  67   VERIFY( pos05 == pos06 );
  68
  69   // cur
  70   // NB: see library issues list 136. It's the v-3 interp that seekg
  71   // only sets the input buffer, or else istreams with buffers that
  72   // have _M_mode == ios_base::out will fail to have consistency
  73   // between seekg and tellg.
  74   state01 = is01.rdstate();
  75   is01.seekg(10, std::ios_base::cur);
  76   state02 = is01.rdstate();
  77   pos01 = is01.tellg();
  78   VERIFY( pos01 == pos02 + off_type(10) );
  79   VERIFY( state01 == state02 );
  80   pos02 = is01.tellg();
  81   VERIFY( pos02 == pos01 );
  82 }
  83
  84 int main()
  85 {
  86   test04();
  87   return 0;
  88 }