https://gcc.gnu.org/bugzilla/show_bug.cgi?id=57376
mauro russo <ing.russomauro at gmail dot com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |ing.russomauro at gmail dot com --- Comment #2 from mauro russo <ing.russomauro at gmail dot com> --- Still present in gcc 14.2 (checked on godbolt). As contribute, it disappears by enabling one of the two commented lines in the following: namespace B { class Woo; } namespace { //using namespace B; // solves the compilation error //using B::Woo; // also solves the compilation error struct Foo { Foo* F1(B::Woo *); Foo* F2(B::Woo *); }; } namespace B { class Boo:Foo { friend Foo *Foo::F1(B::Woo *); // ok friend Foo *Foo::F2(Woo *); // error }; }