http://gcc.gnu.org/bugzilla/show_bug.cgi?id=51158
Bug #: 51158 Summary: C++ std::real() is broken when using -std=c++0x mode Classification: Unclassified Product: gcc Version: 4.4.5 Status: UNCONFIRMED Severity: major Priority: P3 Component: libstdc++ AssignedTo: unassig...@gcc.gnu.org ReportedBy: mtall....@gmail.com Created attachment 25836 --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=25836 source code demonstrating the bug With -std=c++0x mode, std::real() from <complex> appears to be broken. Valid C++ code compiles fine without -std=c++0x mode. More specifically, with -std=c++0x enabled, std::real() is confused with a user version of real(), which is in a separate namespace. In the attached program, the output of the compiled program should be: A.val = (123,456) B.val = 123 When using -std=c++0x, the following error occurs during compilation: real_bug.cpp: In function ‘int main(int, char**)’: real_bug.cpp:93: error: no match for ‘operator=’ in ‘B = std::real [with _Tp = mylib::Mat<std::complex<double> >](A)’ real_bug.cpp:52: note: candidates are: mylib::Mat<double>& mylib::Mat<double>::operator=(const mylib::Mat<double>&) Note that the compiler wants to call std::real(), while it should be calling mylib::real() instead. I'm using gcc 4.4.5 from Scientific Linux 6.1 (a clone of Red Hat Enterprise Linux 6.1) on an x86_64 machine. I've also tried clang++ 2.8, and the code compiles fine. > gcc -v Using built-in specs. Target: x86_64-redhat-linux Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-bootstrap --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk --disable-dssi --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre --enable-libgcj-multifile --enable-java-maintainer-mode --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libjava-multilib --with-ppl --with-cloog --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux Thread model: posix gcc version 4.4.5 20110214 (Red Hat 4.4.5-6) (GCC)