https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58091
S. Davis Herring <herring at lanl dot gov> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |herring at lanl dot gov --- Comment #6 from S. Davis Herring <herring at lanl dot gov> --- The lookup is ambiguous: generally a < forces ordinary lookup to take place, even in contexts like declarator-ids where sometimes other possibilities apply (like defining a hidden friend). (ADL can still rescue "f<0>(x)", but only because nowadays there is a rule to form a template-id there if f isn't found by lookup at all.) The language does not in general filter lookup possibilities by which results would work in the syntactic context.