parser.c (cp_parser_diagnose_invalid_type_name): Mention that concept is also…

parser.c (cp_parser_diagnose_invalid_type_name): Mention that concept is also available with -std=c++2a.

	* parser.c (cp_parser_diagnose_invalid_type_name): Mention
	that concept is also available with -std=c++2a.

From-SVN: r279066

gcc/cp/ChangeLog

 2019-12-06  Jakub Jelinek  <jakub@redhat.com>
 
+	* parser.c (cp_parser_diagnose_invalid_type_name): Mention
+	that concept is also available with -std=c++2a.
+
 	PR c++/92831 - CWG 1299, not extending temporary lifetime for ?:
 	* cp-tree.h (extend_ref_init_temps): Add a new argument with NULL
 	default arg.

gcc/cp/parser.c

@@ -3367,7 +3367,8 @@ cp_parser_diagnose_invalid_type_name (cp_parser *parser, tree id,
 	inform (location, "C++20 %<constinit%> only available with "
 		"%<-std=c++2a%> or %<-std=gnu++2a%>");
       else if (!flag_concepts && id == ridpointers[(int)RID_CONCEPT])
-	inform (location, "%<concept%> only available with %<-fconcepts%>");
+	inform (location, "%<concept%> only available with %<-std=c++2a%> or "
+		"%<-fconcepts%>");
       else if (processing_template_decl && current_class_type
 	       && TYPE_BINFO (current_class_type))
 	{