diff -r 000000000000 -r 6474c204b198 mfbt/NumericLimits.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mfbt/NumericLimits.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,40 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+/* Compatibility with std::numeric_limits<char16_t>. */
+
+#ifndef mozilla_NumericLimits_h
+#define mozilla_NumericLimits_h
+
+#include "mozilla/Char16.h"
+
+#include <limits>
+#include <stdint.h>
+
+namespace mozilla {
+
+/**
+ * The NumericLimits class provides a compatibility layer with std::numeric_limits
+ * for char16_t, otherwise it is exactly the same as std::numeric_limits.
+ * Code which does not need std::numeric_limits<char16_t> should avoid using
+ * NumericLimits.
+ */
+template<typename T>
+class NumericLimits : public std::numeric_limits<T>
+{
+};
+
+#ifdef MOZ_CHAR16_IS_NOT_WCHAR
+template<>
+class NumericLimits<char16_t> : public std::numeric_limits<uint16_t>
+{
+  // char16_t and uint16_t numeric limits should be exactly the same.
+};
+#endif
+
+} // namespace mozilla
+
+#endif /* mozilla_NumericLimits_h */