From c51e2867f50de63db151310da03b829d667becc9 Mon Sep 17 00:00:00 2001
From: Anders Hejlsberg <andersh@microsoft.com>
Date: Thu, 19 Jan 2017 14:47:26 -0800
Subject: [PATCH] Allow object intersection types in class implements clauses

---
 src/compiler/checker.ts | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 1ca1cd9cf74..450fcfe1da4 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -18411,8 +18411,7 @@ namespace ts {
                     if (produceDiagnostics) {
                         const t = getTypeFromTypeNode(typeRefNode);
                         if (t !== unknownType) {
-                            const declaredType = getObjectFlags(t) & ObjectFlags.Reference ? (<TypeReference>t).target : t;
-                            if (getObjectFlags(declaredType) & ObjectFlags.ClassOrInterface) {
+                            if (isValidBaseType(t)) {
                                 checkTypeAssignableTo(typeWithThis, getTypeWithThisArgument(t, type.thisType), node.name || node, Diagnostics.Class_0_incorrectly_implements_interface_1);
                             }
                             else {