https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96605
Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |ice-on-invalid-code --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- I think this was fixed in GCC 11.1.0: I get: <source>:7:11: error: 'Expression_Term' does not constrain a type 7 | template <Expression_Term ... > struct dictionary {}; | ^~~~~~~~~~~~~~~ And I think the code is invalid too. If I change the first two concepts to: template <typename T> concept Expression_Term = true; template <typename T> concept Array_Term = true; We accept the code as expected.