https://gcc.gnu.org/bugzilla/show_bug.cgi?id=93279
--- Comment #6 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
This passes dg.exp but I haven't convinced it's the right solution so haven't
posted it...
--- a/gcc/cp/pt.c
+++ b/gcc/cp/pt.c
@@ -21849,8 +21849,12 @@ type_unification_real (tree tparms,
NULL_TREE);
if (!uses_template_parms (substed))
- arg = convert_template_argument (parm, substed, full_targs,
- complain, i, NULL_TREE);
+ {
+ ++processing_template_decl;
+ arg = convert_template_argument (parm, substed, full_targs,
+ complain, i, NULL_TREE);
+ --processing_template_decl;
+ }
else if (saw_undeduced == 1)
arg = NULL_TREE;
else
