/* * Copyright (C) 2013 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. */ #ifndef WTF_Ref_h #define WTF_Ref_h #include "Noncopyable.h" namespace WTF { template<typename T> class PassRef; template<typename T> class Ref { WTF_MAKE_NONCOPYABLE(Ref) public: Ref(T& object) : m_ptr(&object) { m_ptr->ref(); } template<typename U> Ref(PassRef<U> reference) : m_ptr(&reference.leakRef()) { } ~Ref() { m_ptr->deref(); } Ref& operator=(T& object) { object.ref(); m_ptr->deref(); m_ptr = &object; return *this; } template<typename U> Ref& operator=(PassRef<U> reference) { m_ptr->deref(); m_ptr = &reference.leakRef(); return *this; } const T* operator->() const { return m_ptr; } T* operator->() { return m_ptr; } const T& get() const { return *m_ptr; } T& get() { return *m_ptr; } template<typename U> PassRef<T> replace(PassRef<U>) WARN_UNUSED_RETURN; private: T* m_ptr; }; template<typename T> template<typename U> inline PassRef<T> Ref<T>::replace(PassRef<U> reference) { auto oldReference = adoptRef(*m_ptr); m_ptr = &reference.leakRef(); return oldReference; } } // namespace WTF using WTF::Ref; #endif // WTF_Ref_h