https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67433
--- Comment #4 from xuejuncao <xuejuncao at gmail dot com> --- btw, the same code works fine on Mac: $gcc --version Configured with: --prefix=/Library/Developer/CommandLineTools/usr --with-gxx-include-dir=/usr/include/c++/4.2.1 Apple LLVM version 6.1.0 (clang-602.0.53) (based on LLVM 3.6.0svn) Target: x86_64-apple-darwin14.5.0 Thread model: posix