The following invalid testcase is accepted since at least gcc 2.95.3 (pointer to void member should be rejected):
================================== template<typename T> struct A { T A::* p; }; A<void> a; ================================== -- Summary: pointer-to-void member not rejected in template Product: gcc Version: 4.0.0 Status: UNCONFIRMED Keywords: accepts-invalid, monitored Severity: normal Priority: P2 Component: c++ AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: reichelt at gcc dot gnu dot org CC: gcc-bugs at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19894