libstdc++-v3/testsuite/27_io/basic_ostringstream/rdbuf/wchar_t/2832.cc

   1 // Copyright (C) 2004-2014 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 // 27.7.3.2 member functions (ostringstream_members)
  19
  20 #include <sstream>
  21 #include <testsuite_hooks.h>
  22
  23 void
  24 redirect_buffer(std::wios& stream, std::wstreambuf* new_buf)
  25 { stream.rdbuf(new_buf); }
  26
  27 std::wstreambuf*
  28 active_buffer(std::wios& stream)
  29 { return stream.rdbuf(); }
  30
  31 // libstdc++/2832
  32 void test02()
  33 {
  34   bool test __attribute__((unused)) = true;
  35   const wchar_t* strlit01 = L"fuck war";
  36   const std::wstring str00;
  37   const std::wstring str01(strlit01);
  38   std::wstring str02;
  39   std::wstringbuf sbuf(str01);
  40   std::wstreambuf* pbasebuf0 = &sbuf;
  41
  42   std::wostringstream sstrm1;
  43   VERIFY( sstrm1.str() == str00 );
  44   // derived rdbuf() always returns original streambuf, even though
  45   // it's no longer associated with the stream.
  46   std::wstringbuf* const buf1 = sstrm1.rdbuf();
  47   // base rdbuf() returns the currently associated streambuf
  48   std::wstreambuf* pbasebuf1 = active_buffer(sstrm1);
  49   redirect_buffer(sstrm1, &sbuf);
  50   std::wstringbuf* const buf2 = sstrm1.rdbuf();
  51   std::wstreambuf* pbasebuf2 = active_buffer(sstrm1);
  52   VERIFY( buf1 == buf2 );
  53   VERIFY( pbasebuf1 != pbasebuf2 );
  54   VERIFY( pbasebuf2 == pbasebuf0 );
  55
  56   // derived rdbuf() returns the original buf, so str() doesn't change.
  57   VERIFY( sstrm1.str() != str01 );
  58   VERIFY( sstrm1.str() == str00 );
  59   // however, casting the active streambuf to a stringbuf shows what's up:
  60   std::wstringbuf* psbuf = dynamic_cast<std::wstringbuf*>(pbasebuf2);
  61   str02 = psbuf->str();
  62   VERIFY( str02 == str01 );
  63
  64   // How confusing and non-intuitive is this?
  65   // These semantics are a joke, a serious defect, and incredibly lame.
  66 }
  67
  68 int main()
  69 {
  70   test02();
  71   return 0;
  72 }