The following invalid code snippet triggers an ICE on mainline: ================================================================ template<typename...> class A {};
template<int> class A<> {}; template<typename T, typename...U> struct A<T,U...> : A<U...> { A() {} }; A<int> a; ================================================================ bug.cc:3: error: template parameters not used in partial specialization: bug.cc:3: error: '<anonymous>' bug.cc: In constructor 'A<T, U ...>::A() [with T = int, U = ]': bug.cc:10: instantiated from here bug.cc:7: internal compiler error: in build_simple_base_path, at cp/class.c:489 Please submit a full bug report, [etc.] -- Summary: [4.3 regression] ICE with broken specialization of variadic template Product: gcc Version: 4.3.0 Status: UNCONFIRMED Keywords: ice-on-invalid-code, error-recovery, monitored Severity: normal Priority: P3 Component: c++ AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: reichelt at gcc dot gnu dot org http://gcc.gnu.org/bugzilla/show_bug.cgi?id=34756