import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

js/public/UniquePtr.h

@@ -0,0 +1,61 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
+ * vim: set ts=8 sts=4 et sw=4 tw=99:
+ * 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/. */
+
+#ifndef js_UniquePtr_h
+#define js_UniquePtr_h
+
+#include "mozilla/UniquePtr.h"
+
+#include "js/Utility.h"
+
+namespace js {
+
+// Replacement for mozilla::UniquePtr that defaults to js::DefaultDelete.
+template <typename T, typename D = JS::DeletePolicy<T>>
+using UniquePtr = mozilla::UniquePtr<T, D>;
+
+namespace detail {
+
+template<typename T>
+struct UniqueSelector
+{
+  typedef UniquePtr<T> SingleObject;
+};
+
+template<typename T>
+struct UniqueSelector<T[]>
+{
+  typedef UniquePtr<T[]> UnknownBound;
+};
+
+template<typename T, decltype(sizeof(int)) N>
+struct UniqueSelector<T[N]>
+{
+  typedef UniquePtr<T[N]> KnownBound;
+};
+
+} // namespace detail
+
+// Replacement for mozilla::MakeUnique that correctly calls js_new and produces
+// a js::UniquePtr.
+template<typename T, typename... Args>
+typename detail::UniqueSelector<T>::SingleObject
+MakeUnique(Args&&... aArgs)
+{
+  return UniquePtr<T>(js_new<T>(mozilla::Forward<Args>(aArgs)...));
+}
+
+template<typename T>
+typename detail::UniqueSelector<T>::UnknownBound
+MakeUnique(decltype(sizeof(int)) aN) = delete;
+
+template<typename T, typename... Args>
+typename detail::UniqueSelector<T>::KnownBound
+MakeUnique(Args&&... aArgs) = delete;
+
+} // namespace js
+
+#endif /* js_UniquePtr_h */