Workaround for GCC bug 52595

A.k.a. C++ Core Language issue 325

Refs:
- https://gcc.gnu.org/bugzilla/show_bug.cgi?id=52595
- http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#325
- http://stackoverflow.com/a/23955214