@@ -12682,7 +12682,13 @@ gen_elem_of_pack_expansion_instantiation (tree pattern,
t = tsubst_expr (pattern, args, complain, in_decl,
/*integral_constant_expression_p=*/false);
else
- t = tsubst (pattern, args, complain, in_decl);
+ {
+ t = tsubst (pattern, args, complain, in_decl);
+ if (is_auto (t) && !ith_elem_is_expansion)
+ /* When expanding the fake auto... pack expansion from add_capture, we
+ need to mark that the expansion is no longer a pack. */
+ TEMPLATE_TYPE_PARAMETER_PACK (t) = false;
+ }
/* If the Ith argument pack element is a pack expansion, then
the Ith element resulting from the substituting is going to
new file mode 100644
@@ -0,0 +1,18 @@
+// PR c++/102629
+// { dg-do compile { target c++20 } }
+
+template <class T> T&& forward(T&);
+template <class T> T&& forward(T&&);
+
+struct S {};
+
+template <typename... Args>
+void foo(Args&&... args) {
+ [...args = forward<Args> /*(args)*/] { // { dg-error "" }
+ [](auto...) { } (forward<Args>(args)...);
+ };
+}
+
+void bar( ) {
+ foo(S{});
+}