https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82247
--- Comment #5 from Joël Lamotte <mjklaim at gmail dot com> --- I'll have to recheck when I have access to a proper computer, but that indeed would explain this(weird) behavior. My understanding was that for basic types, ADL would still work using global namespace, which is why I didn't expect the int case to fail.
