===================================================================
@@ -7486,7 +7486,7 @@ build_over_call (struct z_candidate *cand, int fla
}
if (!already_used
- && !mark_used (fn))
+ && !mark_used (fn, complain))
return error_mark_node;
if (DECL_VINDEX (fn) && (flags & LOOKUP_NONVIRTUAL) == 0
===================================================================
@@ -5037,7 +5037,8 @@ mark_used (tree decl, tsubst_flags_t complain)
&& uses_template_parms (DECL_TI_ARGS (decl)))
return true;
- require_deduced_type (decl);
+ if (complain & tf_error)
+ require_deduced_type (decl);
/* If we don't need a value, then we don't need to synthesize DECL. */
if (cp_unevaluated_operand != 0)
===================================================================
@@ -0,0 +1,19 @@
+// PR c++/65340
+// { dg-do compile { target c++14 } }
+
+template <typename Type> Type constant;
+namespace reflect {
+namespace functors {
+ struct recurse { auto operator()(, ); }; // { dg-error "expected" }
+}
+ auto &recurse = constant < functors :: recurse > ;
+}
+namespace functors {
+struct traverse {
+ template <typename Algo, typename Value>
+ auto operator()(Algo, Value) -> decltype(reflect
+ :: recurse(0, 0));
+};
+}
+auto &traverse = constant < functors :: traverse > ;
+operator()()->decltype(traverse(0, 0)) // { dg-error "use of|expected" }