Require a _qualified-id_ for non-namespace using

Author: hsutter

regression-tests/test-results/version

@@ -1,5 +1,5 @@
 
-cppfront compiler v0.3.0   Build 9104:1031
+cppfront compiler v0.3.0   Build 9104:1043
 Copyright(c) Herb Sutter   All rights reserved
 
 SPDX-License-Identifier: CC-BY-NC-ND-4.0

source/build.info

@@ -1 +1 @@
-"9104:1031"
+"9104:1043"

source/parse.h

@@ -7232,7 +7232,7 @@ class parser
 
 
     //G using-statement:
-    //G     'using' id-expression ';'
+    //G     'using' qualified-id ';'
     //G     'using' 'namespace' id-expression ';'
     //G
     auto using_statement()
@@ -7256,6 +7256,10 @@ class parser
             error(std::string{"expected valid id-expression after 'using"} + (n->for_namespace ? " namespace" : "") + "'");
             return {};
         }
+        if (!n->for_namespace && !id->is_qualified()) {
+            error("'using' for a specific name (not 'using namespace') must specify a qualified name", false);
+            return {};
+        }
 
         n->id = std::move(id);