@@ -23304,14 +23304,24 @@ type_unification_real (tree tparms,
return unify_parameter_deduction_failure (explain_p, tparm);
}
+ /* During partial ordering, we deduce dependent template args. */
+ bool any_dependent_targs = false;
+
/* Now substitute into the default template arguments. */
for (i = 0; i < ntparms; i++)
{
tree targ = TREE_VEC_ELT (targs, i);
tree tparm = TREE_VEC_ELT (tparms, i);
- if (targ || tparm == error_mark_node)
+ if (targ)
+ {
+ if (!any_dependent_targs && dependent_template_arg_p (targ))
+ any_dependent_targs = true;
+ continue;
+ }
+ if (tparm == error_mark_node)
continue;
+
tree parm = TREE_VALUE (tparm);
tree arg = TREE_PURPOSE (tparm);
reopen_deferring_access_checks (*checks);
@@ -23347,9 +23357,9 @@ type_unification_real (tree tparms,
do this substitution without processing_template_decl. This
is important if the default argument contains something that
might be instantiation-dependent like access (87480). */
- processing_template_decl_sentinel s;
+ processing_template_decl_sentinel s (!any_dependent_targs);
tree substed = NULL_TREE;
- if (saw_undeduced == 1)
+ if (saw_undeduced == 1 && !any_dependent_targs)
{
/* First instatiate in template context, in case we still
depend on undeduced template parameters. */
@@ -23372,7 +23382,7 @@ type_unification_real (tree tparms,
complain, i, NULL_TREE);
else if (saw_undeduced == 1)
arg = NULL_TREE;
- else
+ else if (!any_dependent_targs)
arg = error_mark_node;
}
new file mode 100644
@@ -0,0 +1,8 @@
+// PR c++/105481
+// { dg-do compile { target c++11 } }
+
+template<unsigned> struct uint;
+template<unsigned N> uint<N> f(const uint<N> &);
+template<unsigned N, typename T, typename = uint<N>> uint<N> f(T);
+using X = uint<1>;
+X (*fp)(X const &) = f;