https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61216
Daniel Krügler <daniel.kruegler at googlemail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |daniel.kruegler@googlemail. | |com --- Comment #1 from Daniel Krügler <daniel.kruegler at googlemail dot com> --- Your comparison doesn't make sense, because in your second example there is no ADL involved. Change it to class C {}; namespace N { void f(C&) {} } void f(C&) {} int main() { using N::f; C c; f(c); } and you will notice the same ambiguity.