// 2001-05-24 Benjamin Kosnik // Copyright (C) 2001, 2002, 2003, 2009 Free Software Foundation, Inc. // // This file is part of the GNU ISO C++ Library. This library is free // software; you can redistribute it and/or modify it under the // terms of the GNU General Public License as published by the // Free Software Foundation; either version 3, or (at your option) // any later version. // This library is distributed in the hope that it will be useful, // but WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // You should have received a copy of the GNU General Public License along // with this library; see the file COPYING3. If not see // . // 27.7.6 member functions (stringstream_members) #include #include void redirect_buffer(std::ios& stream, std::streambuf* new_buf) { stream.rdbuf(new_buf); } std::streambuf* active_buffer(std::ios& stream) { return stream.rdbuf(); } // libstdc++/2832 void test02() { bool test __attribute__((unused)) = true; const char* strlit01 = "fuck war"; const std::string str00; const std::string str01(strlit01); std::string str02; std::stringbuf sbuf(str01); std::streambuf* pbasebuf0 = &sbuf; std::stringstream sstrm1; VERIFY( sstrm1.str() == str00 ); // derived rdbuf() always returns original streambuf, even though // it's no longer associated with the stream. std::stringbuf* const buf1 = sstrm1.rdbuf(); // base rdbuf() returns the currently associated streambuf std::streambuf* pbasebuf1 = active_buffer(sstrm1); redirect_buffer(sstrm1, &sbuf); std::stringbuf* const buf2 = sstrm1.rdbuf(); std::streambuf* pbasebuf2 = active_buffer(sstrm1); VERIFY( buf1 == buf2 ); VERIFY( pbasebuf1 != pbasebuf2 ); VERIFY( pbasebuf2 == pbasebuf0 ); // derived rdbuf() returns the original buf, so str() doesn't change. VERIFY( sstrm1.str() != str01 ); VERIFY( sstrm1.str() == str00 ); // however, casting the active streambuf to a stringbuf shows what's up: std::stringbuf* psbuf = dynamic_cast(pbasebuf2); str02 = psbuf->str(); VERIFY( str02 == str01 ); // How confusing and non-intuitive is this? // These semantics are a joke, a serious defect, and incredibly lame. } int main() { test02(); return 0; }