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

   1 // 2000-06-29 bkoz
   2
   3 // Copyright (C) 2000-2023 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 // stringstreams
  33 void test05(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.tst";
  40   std::ifstream if01(str_lit01);
  41   std::ifstream if02(str_lit01);
  42   std::ifstream if03(str_lit01);
  43   VERIFY( if01.good() );
  44   VERIFY( if02.good() );
  45   VERIFY( if03.good() );
  46
  47   std::stringbuf strbuf01(std::ios_base::in | std::ios_base::out);
  48   if01 >> &strbuf01;
  49   // initialize stringbufs that are ios_base::out
  50   std::stringbuf strbuf03(strbuf01.str(), std::ios_base::out);
  51   // initialize stringbufs that are ios_base::in
  52   std::stringbuf strbuf02(strbuf01.str(), std::ios_base::in);
  53
  54   std::istream is01(&strbuf01);
  55   std::istream is02(&strbuf02);
  56   std::istream is03(&strbuf03);
  57
  58   // pos_type tellg()
  59   // in | out
  60   pos01 = is01.tellg();
  61   pos02 = is01.tellg();
  62   pos03 = is02.tellg();
  63   pos04 = is02.tellg();
  64   pos05 = is03.tellg();
  65   pos06 = is03.tellg();
  66
  67   // istream& seekg(pos_type)
  68   // istream& seekg(off_type, ios_base::seekdir)
  69
  70   // cur
  71   // NB: see library issues list 136. It's the v-3 interp that seekg
  72   // only sets the input buffer, or else istreams with buffers that
  73   // have _M_mode == ios_base::out will fail to have consistency
  74   // between seekg and tellg.
  75   state01 = is01.rdstate();
  76   is01.seekg(10, std::ios_base::cur);
  77   state02 = is01.rdstate();
  78   pos01 = is01.tellg();
  79   VERIFY( pos01 == pos02 + off_type(10) );
  80   VERIFY( state01 == state02 );
  81   pos02 = is01.tellg();
  82   VERIFY( pos02 == pos01 );
  83
  84   state01 = is02.rdstate();
  85   is02.seekg(10, std::ios_base::cur);
  86   state02 = is02.rdstate();
  87   pos03 = is02.tellg();
  88   VERIFY( pos03 == pos04 + off_type(10) );
  89   VERIFY( state01 == state02 );
  90   pos04 = is02.tellg();
  91   VERIFY( pos03 == pos04 );
  92
  93   state01 = is03.rdstate();
  94   is03.seekg(10, std::ios_base::cur);
  95   state02 = is03.rdstate();
  96   pos05 = is03.tellg();
  97   VERIFY( pos05 == pos06 ); // as only out buffer
  98   VERIFY( state01 != state02 );
  99   pos06 = is03.tellg();
 100   VERIFY( pos05 == pos06 );
 101
 102   // beg
 103   state01 = is01.rdstate();
 104   is01.seekg(20, std::ios_base::beg);
 105   state02 = is01.rdstate();
 106   pos01 = is01.tellg();
 107   VERIFY( pos01 == pos02 + off_type(10) );
 108   VERIFY( state01 == state02 );
 109   pos02 = is01.tellg();
 110   VERIFY( pos02 == pos01 );
 111
 112   state01 = is02.rdstate();
 113   is02.seekg(20, std::ios_base::beg);
 114   state02 = is02.rdstate();
 115   pos03 = is02.tellg();
 116   VERIFY( pos03 == pos04 + off_type(10) );
 117   VERIFY( state01 == state02 );
 118   pos04 = is02.tellg();
 119   VERIFY( pos03 == pos04 );
 120
 121   state01 = is03.rdstate();
 122   is03.seekg(20, std::ios_base::beg);
 123   state02 = is03.rdstate();
 124   pos05 = is03.tellg();
 125   VERIFY( pos05 == pos06 ); // as only out buffer
 126   VERIFY( state01 == state02 );
 127   pos06 = is03.tellg();
 128   VERIFY( pos05 == pos06 );
 129 }
 130
 131 int main()
 132 {
 133   test05();
 134   return 0;
 135 }