The following invalid code snippet triggers an ICE on mainline since today:
============================================================= template<typename... T, template<T> class X> void foo(X<0>); ============================================================= bug.cc:1: error: parameter packs not expanded with `...': bug.cc:1: note: 'T' bug.cc:1: internal compiler error: tree check: expected tree_vec, have type_pack_expansion in coerce_template_parameter_pack, at cp/pt.c:5054 Please submit a full bug report, [etc.] -- Summary: [4.3 regression] ICE with parameter pack in template constant parameter 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=35022