diff -r 000000000000 -r 6474c204b198 js/src/yarr/MatchResult.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/js/src/yarr/MatchResult.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,78 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ *
+ * Copyright (C) 2012 Apple Inc. All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
+ * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
+ * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef yarr_MatchResult_h
+#define yarr_MatchResult_h
+
+#include "yarr/wtfbridge.h"
+
+typedef uint64_t EncodedMatchResult;
+
+struct MatchResult {
+    MatchResult(int start, int end)
+        : start(start)
+        , end(end)
+    {
+    }
+
+#if !WTF_CPU_X86_64 || WTF_PLATFORM_WIN
+    explicit MatchResult(EncodedMatchResult encoded)
+    {
+        union u {
+            uint64_t encoded;
+            struct s {
+                int start;
+                int end;
+            } split;
+        } value;
+        value.encoded = encoded;
+        start = value.split.start;
+        end = value.split.end;
+    }
+#endif
+
+    static MatchResult failed()
+    {
+        return MatchResult(int(WTF::notFound), 0);
+    }
+
+    operator bool()
+    {
+        return start != int(WTF::notFound);
+    }
+
+    bool empty()
+    {
+        return start == end;
+    }
+
+    // strings are limited to a length of 2^28. So this is safe
+    int start;
+    int end;
+};
+
+#endif /* yarr_MatchResult_h */