struct base { virtual void foo() = 0; }; struct d1 : public virtual base { virtual void foo() {} }; struct d2 : public virtual base { virtual void foo() {} }; struct der : public d1, public d2 { };
gets you: ~/ootbc/members/src$ g++ foo.cc foo.cc:4: error: no unique final overrider for `virtual void base::foo()' in `der' foo.cc:4: error: no unique final overrider for `virtual void base::foo()' in `der' foo.cc:4: error: no unique final overrider for `virtual void base::foo()' in `der' foo.cc:4: error: no unique final overrider for `virtual void base::foo()' in `der' -- Summary: multiple diagnostics Product: gcc Version: 3.4.0 Status: UNCONFIRMED Severity: normal Priority: P2 Component: c++ AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: igodard at pacbell dot net CC: gcc-bugs at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=21983