On Mon, 17 Dec 2018 at 15:24, Jakub Jelinek <ja...@redhat.com> wrote: > > On Mon, Dec 17, 2018 at 03:11:03PM +0000, Jonathan Wakely wrote: > > --- a/gcc/cp/constraint.cc > > +++ b/gcc/cp/constraint.cc > > @@ -563,7 +563,7 @@ expand_concept (tree decl, tree args) > > ++processing_template_decl; > > tree result = tsubst_expr (def, args, tf_none, NULL_TREE, true); > > --processing_template_decl; > > - if (result == error_mark_node) > > + if (result == error_mark_node || t == NULL_TREE) > > t == NULL_TREE or result == NULL_TREE ?
D'oh, sorry. It should be result (as Nick showed originally, but not as a patch).
