libstdc++-v3/testsuite/27_io/basic_filebuf/sungetc/char/2-io.cc

   1 // 2001-05-21 Benjamin Kosnik  <bkoz@redhat.com>
   2
   3 // Copyright (C) 2001-2019 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 // 27.8.1.4 Overridden virtual functions
  21
  22 // { dg-require-fileio "" }
  23
  24 #include <fstream>
  25 #include <testsuite_hooks.h>
  26 #include <testsuite_io.h>
  27
  28 // @require@ %-*.tst %-*.txt
  29 // @diff@ %-*.tst %*.txt
  30
  31 const char name_01[] = "tmp_sungetc_2io.tst"; // empty file, need to create
  32
  33 void test01()
  34 {
  35   using namespace std;
  36   using namespace __gnu_test;
  37
  38   typedef filebuf::int_type     int_type;
  39   typedef filebuf::traits_type  traits_type;
  40   typedef size_t                size_type;
  41
  42   streamsize                    strmsz_1, strmsz_2;
  43   int_type                      c1, c2;
  44
  45   // int_type sungetc()
  46   // if in_cur not avail, return pbackfail(), else decrement and
  47   // return to_int_type(*gptr())
  48
  49   // in | out
  50   {
  51     constraint_filebuf fb_01;
  52     fb_01.pubsetbuf(0, 0);
  53     fb_01.open(name_01, ios_base::out | ios_base::in | ios_base::trunc);
  54     VERIFY( fb_01.unbuffered() );
  55     fb_01.sputc('u');
  56     fb_01.sputc('v');
  57     fb_01.pubseekoff(-1, std::ios_base::end);
  58     fb_01.sbumpc();
  59     strmsz_1 = fb_01.in_avail();
  60     c2 = fb_01.sungetc();
  61     strmsz_2 = fb_01.in_avail();
  62     VERIFY( c2 == 'v' ); //  VERIFY( c2 != traits_type::eof() );
  63     VERIFY( strmsz_1 + 1 == strmsz_2 );
  64     //test for _in_cur == _in_end
  65     fb_01.pubseekoff(0, std::ios_base::end);
  66     strmsz_1 = fb_01.in_avail(); // -1 cuz at the end
  67     c1 = fb_01.sgetc();
  68     c2 = fb_01.sungetc();
  69     strmsz_2 = fb_01.in_avail(); // 1
  70     fb_01.sgetc();
  71     VERIFY( c1 != c2 );
  72     VERIFY( strmsz_2 != strmsz_1 );
  73     VERIFY( strmsz_2 == 1 );
  74     VERIFY( fb_01.unbuffered() );
  75   }
  76 }
  77
  78 int main()
  79 {
  80   test01();
  81   return 0;
  82 }