[Bug c++/55203] No unused warning for variables of non-trivial types

[l.lunak at suse dot cz]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55203

--- Comment #5 from Lubos Lunak <l.lunak at suse dot cz> ---
Gcc patch is in, r200941.

Keeping open for libstdc++ to use the attribute for its relevant classes. I can
try to submit a patch when I find the time, but I doubt I'll get past the most
obvious classes, so anyone more knowledgeable about libstdc++ can feel free.