http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55671
--- Comment #9 from Manuel López-Ibáñez <manu at gcc dot gnu.org> 2012-12-13 13:24:51 UTC --- Wsign-conversion was disabled for g++ by explicit request. I don't remember the details and Google seems unable to find the relevant discussion in gcc-patches.
