/* | |
* Copyright (C) 2009 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 "Assertions.h" | |
#include "OwnPtrCommon.h" | |
#include "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 { | |
public: | |
typedef typename RemovePointer<T>::Type ValueType; | |
typedef ValueType* PtrType; | |
PassOwnPtr(PtrType ptr = 0) : m_ptr(ptr) { } | |
// 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 really have a need to use real const PassOwnPtrs | |
// anyway. | |
PassOwnPtr(const PassOwnPtr& o) : m_ptr(o.release()) { } | |
template <typename U> PassOwnPtr(const PassOwnPtr<U>& o) : m_ptr(o.release()) { } | |
~PassOwnPtr() { deleteOwnedPtr(m_ptr); } | |
PtrType get() const { return m_ptr; } | |
void clear() { m_ptr = 0; } | |
PtrType release() const { PtrType ptr = m_ptr; m_ptr = 0; return ptr; } | |
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=(T*); | |
PassOwnPtr& operator=(const PassOwnPtr<T>&); | |
template <typename U> PassOwnPtr& operator=(const PassOwnPtr<U>&); | |
private: | |
mutable PtrType m_ptr; | |
}; | |
template <typename T> inline PassOwnPtr<T>& PassOwnPtr<T>::operator=(T* optr) | |
{ | |
T* ptr = m_ptr; | |
m_ptr = optr; | |
ASSERT(!ptr || m_ptr != ptr); | |
if (ptr) | |
deleteOwnedPtr(ptr); | |
return *this; | |
} | |
template <typename T> inline PassOwnPtr<T>& PassOwnPtr<T>::operator=(const PassOwnPtr<T>& optr) | |
{ | |
T* ptr = m_ptr; | |
m_ptr = optr.release(); | |
ASSERT(!ptr || m_ptr != ptr); | |
if (ptr) | |
deleteOwnedPtr(ptr); | |
return *this; | |
} | |
template <typename T> template <typename U> inline PassOwnPtr<T>& PassOwnPtr<T>::operator=(const PassOwnPtr<U>& optr) | |
{ | |
T* ptr = m_ptr; | |
m_ptr = optr.release(); | |
ASSERT(!ptr || m_ptr != ptr); | |
if (ptr) | |
deleteOwnedPtr(ptr); | |
return *this; | |
} | |
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, typename U> inline PassOwnPtr<T> static_pointer_cast(const PassOwnPtr<U>& p) | |
{ | |
return PassOwnPtr<T>(static_cast<T*>(p.release())); | |
} | |
template <typename T, typename U> inline PassOwnPtr<T> const_pointer_cast(const PassOwnPtr<U>& p) | |
{ | |
return PassOwnPtr<T>(const_cast<T*>(p.release())); | |
} | |
template <typename T> inline T* getPtr(const PassOwnPtr<T>& p) | |
{ | |
return p.get(); | |
} | |
} // namespace WTF | |
using WTF::PassOwnPtr; | |
using WTF::const_pointer_cast; | |
using WTF::static_pointer_cast; | |
#endif // WTF_PassOwnPtr_h |