libstdc++-v3/testsuite/27_io/basic_filebuf/seekoff/char/12790-3.cc

   1 // Copyright (C) 2003 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 2, 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 COPYING.  If not, write to the Free
  16 // Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
  17 // USA.
  18
  19 // 27.8.1.4 Overridden virtual functions
  20
  21 // { dg-require-fileio "" }
  22
  23 #include <locale>
  24 #include <fstream>
  25 #include <testsuite_hooks.h>
  26
  27 class Cvt : public std::codecvt<char, char, std::mbstate_t>
  28 {
  29 public:
  30   mutable bool unshift_called;
  31
  32   Cvt()
  33   : unshift_called(false)
  34   { }
  35
  36 protected:
  37   bool
  38   do_always_noconv() const throw()
  39   { return false; }
  40
  41   int
  42   do_encoding() const throw()
  43   { return -1; }
  44
  45   std::codecvt_base::result
  46   do_unshift(std::mbstate_t&, char* to, char*, char*& to_next) const
  47   {
  48     unshift_called = true;
  49     to_next = to;
  50     return std::codecvt_base::ok;
  51   }
  52 };
  53
  54 // libstdc++/12790
  55 // basic_filebuf::seekoff() should call codecvt::unshift(),
  56 // but only if writing
  57 void test01()
  58 {
  59   using namespace std;
  60
  61   bool test __attribute__((unused)) = true;
  62   const char* name = "tmp_seekoff_12790";
  63
  64   Cvt* cvt = new Cvt;
  65   locale loc(locale::classic(), cvt);
  66
  67   filebuf fb;
  68   fb.pubimbue(loc);
  69
  70   fb.open(name, ios_base::out);
  71
  72   VERIFY( !cvt->unshift_called );
  73   fb.pubseekoff(0, ios_base::cur);
  74   VERIFY( !cvt->unshift_called );
  75 }
  76
  77 int main()
  78 {
  79   test01();
  80   return 0;
  81 }