| /* |
| * Copyright (C) 2009, 2010 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_PassOwnPtr_h |
| #define WTF_PassOwnPtr_h |
| |
| #include <wtf/Assertions.h> |
| #include <wtf/NullPtr.h> |
| #include <wtf/OwnPtrCommon.h> |
| #include <wtf/TypeTraits.h> |
| |
| namespace WTF { |
| |
| // Unlike most of our smart pointers, PassOwnPtr can take either the pointer type or the pointed-to type. |
| |
| template<typename T> class OwnPtr; |
| template<typename T> class PassOwnPtr; |
| template<typename T> PassOwnPtr<T> adoptPtr(T*); |
| |
| template<typename T> class PassOwnPtr { |
| public: |
| typedef typename RemovePointer<T>::Type ValueType; |
| typedef ValueType* PtrType; |
| |
| PassOwnPtr() : m_ptr(0) { } |
| PassOwnPtr(std::nullptr_t) : m_ptr(0) { } |
| |
| // It somewhat breaks the type system to allow transfer of ownership out of |
| // a const PassOwnPtr. However, it makes it much easier to work with PassOwnPtr |
| // temporaries, and we don't have a need to use real const PassOwnPtrs anyway. |
| PassOwnPtr(const PassOwnPtr& o) : m_ptr(o.leakPtr()) { } |
| template<typename U> PassOwnPtr(const PassOwnPtr<U>& o) : m_ptr(o.leakPtr()) { } |
| |
| ~PassOwnPtr() { deleteOwnedPtr(m_ptr); } |
| |
| PtrType get() const { return m_ptr; } |
| |
| PtrType leakPtr() const WARN_UNUSED_RETURN; |
| |
| ValueType& operator*() const { ASSERT(m_ptr); return *m_ptr; } |
| PtrType operator->() const { ASSERT(m_ptr); return m_ptr; } |
| |
| bool operator!() const { return !m_ptr; } |
| |
| // This conversion operator allows implicit conversion to bool but not to other integer types. |
| typedef PtrType PassOwnPtr::*UnspecifiedBoolType; |
| operator UnspecifiedBoolType() const { return m_ptr ? &PassOwnPtr::m_ptr : 0; } |
| |
| PassOwnPtr& operator=(const PassOwnPtr&) { COMPILE_ASSERT(!sizeof(T*), PassOwnPtr_should_never_be_assigned_to); return *this; } |
| |
| template<typename U> friend PassOwnPtr<U> adoptPtr(U*); |
| |
| private: |
| explicit PassOwnPtr(PtrType ptr) : m_ptr(ptr) { } |
| |
| // We should never have two OwnPtrs for the same underlying object (otherwise we'll get |
| // double-destruction), so these equality operators should never be needed. |
| template<typename U> bool operator==(const PassOwnPtr<U>&) { COMPILE_ASSERT(!sizeof(U*), OwnPtrs_should_never_be_equal); return false; } |
| template<typename U> bool operator!=(const PassOwnPtr<U>&) { COMPILE_ASSERT(!sizeof(U*), OwnPtrs_should_never_be_equal); return false; } |
| template<typename U> bool operator==(const OwnPtr<U>&) { COMPILE_ASSERT(!sizeof(U*), OwnPtrs_should_never_be_equal); return false; } |
| template<typename U> bool operator!=(const OwnPtr<U>&) { COMPILE_ASSERT(!sizeof(U*), OwnPtrs_should_never_be_equal); return false; } |
| |
| mutable PtrType m_ptr; |
| }; |
| |
| template<typename T> inline typename PassOwnPtr<T>::PtrType PassOwnPtr<T>::leakPtr() const |
| { |
| PtrType ptr = m_ptr; |
| m_ptr = 0; |
| return ptr; |
| } |
| |
| template<typename T, typename U> inline bool operator==(const PassOwnPtr<T>& a, const PassOwnPtr<U>& b) |
| { |
| return a.get() == b.get(); |
| } |
| |
| template<typename T, typename U> inline bool operator==(const PassOwnPtr<T>& a, const OwnPtr<U>& b) |
| { |
| return a.get() == b.get(); |
| } |
| |
| template<typename T, typename U> inline bool operator==(const OwnPtr<T>& a, const PassOwnPtr<U>& b) |
| { |
| return a.get() == b.get(); |
| } |
| |
| template<typename T, typename U> inline bool operator==(const PassOwnPtr<T>& a, U* b) |
| { |
| return a.get() == b; |
| } |
| |
| template<typename T, typename U> inline bool operator==(T* a, const PassOwnPtr<U>& b) |
| { |
| return a == b.get(); |
| } |
| |
| template<typename T, typename U> inline bool operator!=(const PassOwnPtr<T>& a, const PassOwnPtr<U>& b) |
| { |
| return a.get() != b.get(); |
| } |
| |
| template<typename T, typename U> inline bool operator!=(const PassOwnPtr<T>& a, const OwnPtr<U>& b) |
| { |
| return a.get() != b.get(); |
| } |
| |
| template<typename T, typename U> inline bool operator!=(const OwnPtr<T>& a, const PassOwnPtr<U>& b) |
| { |
| return a.get() != b.get(); |
| } |
| |
| template<typename T, typename U> inline bool operator!=(const PassOwnPtr<T>& a, U* b) |
| { |
| return a.get() != b; |
| } |
| |
| template<typename T, typename U> inline bool operator!=(T* a, const PassOwnPtr<U>& b) |
| { |
| return a != b.get(); |
| } |
| |
| template<typename T> inline PassOwnPtr<T> adoptPtr(T* ptr) |
| { |
| return PassOwnPtr<T>(ptr); |
| } |
| |
| template<typename T, typename U> inline PassOwnPtr<T> static_pointer_cast(const PassOwnPtr<U>& p) |
| { |
| return adoptPtr(static_cast<T*>(p.leakPtr())); |
| } |
| |
| template<typename T, typename U> inline PassOwnPtr<T> const_pointer_cast(const PassOwnPtr<U>& p) |
| { |
| return adoptPtr(const_cast<T*>(p.leakPtr())); |
| } |
| |
| template<typename T> inline T* getPtr(const PassOwnPtr<T>& p) |
| { |
| return p.get(); |
| } |
| |
| } // namespace WTF |
| |
| using WTF::PassOwnPtr; |
| using WTF::adoptPtr; |
| using WTF::const_pointer_cast; |
| using WTF::static_pointer_cast; |
| |
| #endif // WTF_PassOwnPtr_h |