[Bug c++/49409] some possible new warnings for strange code

[redi at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49409

--- Comment #1 from Jonathan Wakely <redi at gcc dot gnu.org> 2011-06-14 
22:34:34 UTC ---
some warnings would seem sensible to me

I tried clang++ which only warns about the first two, via
-Wtautological-compare