http://gcc.gnu.org/bugzilla/show_bug.cgi?id=54537
Bug #: 54537 Summary: undiagnosed using-declaration conflicting with used function Classification: Unclassified Product: gcc Version: 4.8.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ AssignedTo: unassig...@gcc.gnu.org ReportedBy: fab...@gcc.gnu.org Noticed while working on DR39, the below is wrongly accepted. A diagnostic is issued if the function f is not used. namespace a { void f(int); } namespace b { void f(int); void g() { f (3); } using a::f; // { dg-error "already declared" } } I have a patch for it.