https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99869
Bug ID: 99869 Summary: ICE: in do_auto_deduction, at cp/pt.c:29620 Product: gcc Version: 11.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: hewillk at gmail dot com Target Milestone: --- This is a small variant of fixed PR 99815. https://godbolt.org/z/jezs4qh3E template <typename...> concept C = true; template <typename... Ts> auto bar(Ts...) { for (C<Ts...> auto c : ""); } <source>:4:42: internal compiler error: in do_auto_deduction, at cp/pt.c:29620 4 | auto bar(Ts...) { for (C<Ts...> auto c : ""); } | ^~ 0x1cfca39 internal_error(char const*, ...) ???:0 0x6ba92b fancy_abort(char const*, int, char const*) ???:0 0x90a724 do_auto_deduction(tree_node*, tree_node*, tree_node*, int, auto_deduction_context, tree_node*, int) ???:0 0x8e126d c_parse_file() ???:0 0xa60292 c_common_parse_file() ???:0 Please submit a full bug report, with preprocessed source if appropriate.