https://gcc.gnu.org/PR95820
https://bugs.gentoo.org/730406
--- a/gcc/cp/decl.c
+++ b/gcc/cp/decl.c
@@ -12029,14 +12029,11 @@ grokdeclarator (const cp_declarator *declarator,
 
 	    /* Handle a late-specified return type.  */
 	    tree late_return_type = declarator->u.function.late_return_type;
-	    if (funcdecl_p
-		/* This is the case e.g. for
-		   using T = auto () -> int.  */
-		|| inner_declarator == NULL)
+	    if (true)
 	      {
 		if (tree auto_node = type_uses_auto (type))
 		  {
-		    if (!late_return_type)
+		    if (!late_return_type && funcdecl_p)
 		      {
 			if (current_class_type
 			    && LAMBDA_TYPE_P (current_class_type))