https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85861
--- Comment #8 from Manuel López-Ibáñez <manu at gcc dot gnu.org> --- (In reply to Eric Gallager from comment #7) > > Does anyone know the history -Wconversion does not already turn on > > sign-conversion warnings for C++ code? This is how historically the C++ FE worked and how Gabriel (at the time diagnostics maintainer) wished to keep it working when the new -Wconversion was implemented: https://gcc.gnu.org/wiki/NewWconversion I don't remember the rationale but it should be somewhere in the gcc-patches archives around 2006-2007. Now I wish I have added it as a comment to the code where the difference is implemented.