/usr/include/boost/variant/detail/forced_return.hpp: In function 'T boost::detail::variant::forced_return() [with T = bool]':
/usr/include/boost/variant/detail/forced_return.hpp:41: warning: 'noreturn' function does return
Modern versions of GCC do not complain on that. Warnings for such outdated versions of compilers won't be fixed in the library, as it may (and would) add warnings on modern compilers.
This is with GCC 4.1.2.