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

   1 // Copyright (C) 2003-2017 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 // 27.8.1.4 Overridden virtual functions
  19
  20 #include <locale>
  21 #include <fstream>
  22 #include <testsuite_hooks.h>
  23
  24 class Cvt : public std::codecvt<wchar_t, char, std::mbstate_t>
  25 {
  26 public:
  27   mutable bool unshift_called;
  28
  29   Cvt()
  30   : unshift_called(false)
  31   { }
  32
  33 protected:
  34   bool
  35   do_always_noconv() const throw()
  36   { return false; }
  37
  38   int
  39   do_encoding() const throw()
  40   { return -1; }
  41
  42   std::codecvt_base::result
  43   do_unshift(std::mbstate_t&, char* to, char*, char*& to_next) const
  44   {
  45     unshift_called = true;
  46     to_next = to;
  47     return std::codecvt_base::ok;
  48   }
  49 };
  50
  51 // libstdc++/12790
  52 // basic_filebuf::seekoff() should call codecvt::unshift(),
  53 // but only if writing
  54 void test01()
  55 {
  56   using namespace std;
  57
  58   const char* name = "tmp_seekoff_12790";
  59
  60   Cvt* cvt = new Cvt;
  61   locale loc(locale::classic(), cvt);
  62
  63   wfilebuf fb;
  64   fb.pubimbue(loc);
  65
  66   fb.open(name, ios_base::out);
  67
  68   VERIFY( !cvt->unshift_called );
  69   fb.pubseekoff(0, ios_base::cur);
  70   VERIFY( !cvt->unshift_called );
  71 }
  72
  73 int main()
  74 {
  75   test01();
  76   return 0;
  77 }