webkitgtk-2.16.5HEADwebkitgtk-2.16.5master

1 files changed, 79 insertions, 0 deletions

diff --git a/Source/WTF/wtf/UniqueRef.h b/Source/WTF/wtf/UniqueRef.h
new file mode 100644
index 000000000..2039950d9
--- /dev/null
+++ b/Source/WTF/wtf/UniqueRef.h
@@ -0,0 +1,79 @@
+/*
+ * Copyright (C) 2016 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. AND ITS CONTRIBUTORS ``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 ITS 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.
+ */
+
+#pragma once
+
+#include <memory>
+#include <wtf/Assertions.h>
+
+namespace WTF {
+
+template<typename T> class UniqueRef;
+
+template<typename T, class... Args>
+UniqueRef<T> makeUniqueRef(Args&&... args)
+{
+    return UniqueRef<T>(*new T(std::forward<Args>(args)...));
+}
+
+template<typename T>
+class UniqueRef {
+public:
+    template <typename U>
+    UniqueRef(UniqueRef<U>&& other)
+        : m_ref(WTFMove(other.m_ref))
+    {
+        ASSERT(m_ref);
+    }
+
+    T& get() { ASSERT(m_ref); return *m_ref; }
+    const T& get() const { ASSERT(m_ref); return *m_ref; }
+
+    T* operator&() { ASSERT(m_ref); return m_ref.get(); }
+    const T* operator&() const { ASSERT(m_ref); return m_ref.get(); }
+
+    T* operator->() { ASSERT(m_ref); return m_ref.get(); }
+    const T* operator->() const { ASSERT(m_ref); return m_ref.get(); }
+    
+    operator T&() { ASSERT(m_ref); return *m_ref; }
+    operator const T&() const { ASSERT(m_ref); return *m_ref; }
+
+private:
+    template<class U, class... Args> friend UniqueRef<U> makeUniqueRef(Args&&...);
+    template<class U> friend class UniqueRef;
+
+    UniqueRef(T& other)
+        : m_ref(&other)
+    {
+        ASSERT(m_ref);
+    }
+
+    std::unique_ptr<T> m_ref;
+};
+
+} // namespace WTF
+
+using WTF::UniqueRef;
+using WTF::makeUniqueRef;