diff -r 000000000000 -r 6474c204b198 dom/xslt/xpath/txExpr.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/xslt/xpath/txExpr.cpp	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,30 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "txExpr.h"
+
+nsresult
+Expr::evaluateToBool(txIEvalContext* aContext, bool& aResult)
+{
+    nsRefPtr<txAExprResult> exprRes;
+    nsresult rv = evaluate(aContext, getter_AddRefs(exprRes));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    aResult = exprRes->booleanValue();
+
+    return NS_OK;
+}
+
+nsresult
+Expr::evaluateToString(txIEvalContext* aContext, nsString& aResult)
+{
+    nsRefPtr<txAExprResult> exprRes;
+    nsresult rv = evaluate(aContext, getter_AddRefs(exprRes));
+    NS_ENSURE_SUCCESS(rv, rv);
+
+    exprRes->stringValue(aResult);
+
+    return NS_OK;
+}