https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99811
--- Comment #1 from 康桓瑋 <hewillk at gmail dot com> --- same form with the different error message: https://godbolt.org/z/hE9n6eEMT #include <concepts> template <typename... Ts> auto f(Ts...) { return []<std::same_as<Ts> auto> {}; } int main() { f(0).template operator()<0>(); } <source>:9:30: internal compiler error: tree check: accessed elt 1 of 'tree_vec' with 0 elts in hash, at cp/constraint.cc:2522 9 | f(0).template operator()<0>(); | ~~~~~~~~~~~~~~~~~~~~~~~~~~~^~ 0x1cfb7f9 internal_error(char const*, ...) ???:0 0x67bcb2 tree_vec_elt_check_failed(int, int, char const*, int, char const*) ???:0 0x73fc50 sat_hasher::hash(sat_entry*) ???:0 0x73b2b7 satisfaction_cache::satisfaction_cache(tree_node*, tree_node*, sat_info) ???:0 0x73efca constraints_satisfied_p(tree_node*, tree_node*) ???:0 0x909bbe do_auto_deduction(tree_node*, tree_node*, tree_node*, int, auto_deduction_context, tree_node*, int) ???:0 0x954187 fn_type_unification(tree_node*, tree_node*, tree_node*, tree_node* const*, unsigned int, tree_node*, unification_kind_t, int, conversion**, bool, bool) ???:0 0x6dec99 build_new_method_call(tree_node*, tree_node*, vec<tree_node*, va_gc, vl_embed>**, tree_node*, int, tree_node**, int) ???:0 0x8e12ad c_parse_file() ???:0 0xa600a2 c_common_parse_file() ???:0 Please submit a full bug report, with preprocessed source if appropriate.
