/* * Copyright (C) 2015 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 WTF_Box_h #define WTF_Box_h #include <wtf/RefPtr.h> #include <wtf/ThreadSafeRefCounted.h> namespace WTF { // Box<T> is a reference-counted pointer to T that allocates T using FastMalloc and prepends a reference // count to it. template<typename T> class Box { public: Box() { } Box(std::nullptr_t) { } template<typename... Arguments> static Box create(Arguments&&... arguments) { Box result; result.m_data = adoptRef(new Data(std::forward<Arguments>(arguments)...)); return result; } T* get() const { return &m_data->value; } T& operator*() const { return m_data->value; } T* operator->() const { return &m_data->value; } explicit operator bool() { return m_data; } private: struct Data : ThreadSafeRefCounted<Data> { template<typename... Arguments> Data(Arguments&&... arguments) : value(std::forward<Arguments>(arguments)...) { } T value; }; RefPtr<Data> m_data; }; } // namespace WTF using WTF::Box; #endif // WTF_Box_h