http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53931
Bug #: 53931 Summary: [C++11] braced function style cast to reference should be prvalue Classification: Unclassified Product: gcc Version: 4.7.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassig...@gcc.gnu.org ReportedBy: hst...@ca.ibm.com Host: powerpc64-unknown-linux-gnu Target: powerpc64-unknown-linux-gnu C++2011 5.2.3 [expr.type.conv] paragraph 3: Similarly, a simple-type-specifier or typename-specifier followed by a braced-init-list creates a temporary object of the specified type direct-list-initialized (8.5.4) with the specified braced-init-list, and its value is that temporary object as a prvalue. In the case below, a braced function-style cast to an rvalue reference type does not behave the same as a prvalue literal with GCC. ### Self-contained source (refBraceCast.cc):> cat refBraceCast.cc typedef int &&ir; void bar(int x) { const_cast<int &&>(ir{x}); } //void zip(int x) { const_cast<int &&>(0); } // fails as expected ### Compiler invocation: g++-4.7.0 -c -std=c++11 refBraceCast.cc; echo rc=$? ### Compiler output: rc=0 ### g++ -v output:> g++-4.7.0 -v Using built-in specs. COLLECT_GCC=g++-4.7.0 COLLECT_LTO_WRAPPER=/data/gcc/libexec/gcc/powerpc64-unknown-linux-gnu/4.7.0/lto-wrapper Target: powerpc64-unknown-linux-gnu Configured with: ../gcc-4.7.0/configure --prefix=/data/gcc --program-suffix=-4.7.0 --disable-libssp --disable-libgcj --enable-version-specific-runtime-libs --with-cpu=default32 --enable-secureplt --with-long-double-128 --enable-shared --enable-__cxa_atexit --enable-threads=posix --enable-languages=c,c++,fortran --with-mpfr=/usr/local/ --with-mpc=/usr/local/ --with-gmp=/usr/local/ Thread model: posix gcc version 4.7.0 (GCC)