1 files changed, 10 insertions, 1 deletions
diff --git a/gcc/cp/name-lookup.c b/gcc/cp/name-lookup.c
index ff6d5ee..57ab129 100644
--- a/gcc/cp/name-lookup.c
+++ b/gcc/cp/name-lookup.c
@@ -2268,7 +2268,13 @@ diagnose_name_conflict (tree decl, tree bval)
       && (TREE_CODE (decl) != TYPE_DECL
 	  || DECL_ARTIFICIAL (decl) == DECL_ARTIFICIAL (bval))
       && CP_DECL_CONTEXT (decl) == CP_DECL_CONTEXT (bval))
-    error ("redeclaration of %q#D", decl);
+    {
+      if (concept_definition_p (decl))
+        error ("redeclaration of %q#D with different template parameters",
+               decl);
+      else
+        error ("redeclaration of %q#D", decl);
+    }
   else
     error ("%q#D conflicts with a previous declaration", decl);
 
@@ -2334,6 +2340,9 @@ matching_fn_p (tree one, tree two)
 	return false;
     }
 
+  if (!equivalently_constrained (one, two))
+    return false;
+
   return true;
 }