/* * Copyright (C) 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved. * Copyright (C) 2013 Intel Corporation. All rights reserved. * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Library General Public * License as published by the Free Software Foundation; either * version 2 of the License, or (at your option) any later version. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Library General Public License for more details. * * You should have received a copy of the GNU Library General Public License * along with this library; see the file COPYING.LIB. If not, write to * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, * Boston, MA 02110-1301, USA. * */ #ifndef WTF_OwnPtr_h #define WTF_OwnPtr_h #include "wtf/HashTableDeletedValueType.h" #include "wtf/Noncopyable.h" #include "wtf/NullPtr.h" #include "wtf/OwnPtrCommon.h" #include <algorithm> namespace WTF { template<typename T> class PassOwnPtr; template<typename T> class OwnPtr { #if COMPILER_SUPPORTS(CXX_RVALUE_REFERENCES) // If rvalue references are not supported, the copy constructor is // public so OwnPtr cannot be marked noncopyable. See note below. WTF_MAKE_NONCOPYABLE(OwnPtr); #endif WTF_DISALLOW_CONSTRUCTION_FROM_ZERO(OwnPtr); public: typedef typename RemoveExtent<T>::Type ValueType; typedef ValueType* PtrType; OwnPtr() : m_ptr(0) { } OwnPtr(std::nullptr_t) : m_ptr(0) { } // See comment in PassOwnPtr.h for why this takes a const reference. OwnPtr(const PassOwnPtr<T>&); template<typename U> OwnPtr(const PassOwnPtr<U>&, EnsurePtrConvertibleArgDecl(U, T)); // Hash table deleted values, which are only constructed and never copied or destroyed. OwnPtr(HashTableDeletedValueType) : m_ptr(hashTableDeletedValue()) { } bool isHashTableDeletedValue() const { return m_ptr == hashTableDeletedValue(); } #if !COMPILER_SUPPORTS(CXX_RVALUE_REFERENCES) // This copy constructor is used implicitly by gcc when it generates // transients for assigning a PassOwnPtr<T> object to a stack-allocated // OwnPtr<T> object. It should never be called explicitly and gcc // should optimize away the constructor when generating code. OwnPtr(const OwnPtr&); #endif ~OwnPtr() { OwnedPtrDeleter<T>::deletePtr(m_ptr); m_ptr = 0; } PtrType get() const { return m_ptr; } void clear(); PassOwnPtr<T> release(); PtrType leakPtr() WARN_UNUSED_RETURN; ValueType& operator*() const { ASSERT(m_ptr); return *m_ptr; } PtrType operator->() const { ASSERT(m_ptr); return m_ptr; } ValueType& operator[](std::ptrdiff_t i) const; bool operator!() const { return !m_ptr; } // This conversion operator allows implicit conversion to bool but not to other integer types. typedef PtrType OwnPtr::*UnspecifiedBoolType; operator UnspecifiedBoolType() const { return m_ptr ? &OwnPtr::m_ptr : 0; } OwnPtr& operator=(const PassOwnPtr<T>&); OwnPtr& operator=(std::nullptr_t) { clear(); return *this; } template<typename U> OwnPtr& operator=(const PassOwnPtr<U>&); #if COMPILER_SUPPORTS(CXX_RVALUE_REFERENCES) OwnPtr(OwnPtr&&); template<typename U> OwnPtr(OwnPtr<U>&&); OwnPtr& operator=(OwnPtr&&); template<typename U> OwnPtr& operator=(OwnPtr<U>&&); #endif void swap(OwnPtr& o) { std::swap(m_ptr, o.m_ptr); } static T* hashTableDeletedValue() { return reinterpret_cast<T*>(-1); } private: #if !COMPILER_SUPPORTS(CXX_RVALUE_REFERENCES) // If rvalue references are supported, noncopyable takes care of this. OwnPtr& operator=(const OwnPtr&); #endif // 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 OwnPtr<U>&) const { COMPILE_ASSERT(!sizeof(U*), OwnPtrs_should_never_be_equal); return false; } template<typename U> bool operator!=(const OwnPtr<U>&) const { COMPILE_ASSERT(!sizeof(U*), OwnPtrs_should_never_be_equal); return false; } template<typename U> bool operator==(const PassOwnPtr<U>&) const { COMPILE_ASSERT(!sizeof(U*), OwnPtrs_should_never_be_equal); return false; } template<typename U> bool operator!=(const PassOwnPtr<U>&) const { COMPILE_ASSERT(!sizeof(U*), OwnPtrs_should_never_be_equal); return false; } PtrType m_ptr; }; template<typename T> inline OwnPtr<T>::OwnPtr(const PassOwnPtr<T>& o) : m_ptr(o.leakPtr()) { } template<typename T> template<typename U> inline OwnPtr<T>::OwnPtr(const PassOwnPtr<U>& o, EnsurePtrConvertibleArgDefn(U, T)) : m_ptr(o.leakPtr()) { COMPILE_ASSERT(!IsArray<T>::value, Pointers_to_array_must_never_be_converted); } template<typename T> inline void OwnPtr<T>::clear() { PtrType ptr = m_ptr; m_ptr = 0; OwnedPtrDeleter<T>::deletePtr(ptr); } template<typename T> inline PassOwnPtr<T> OwnPtr<T>::release() { PtrType ptr = m_ptr; m_ptr = 0; return PassOwnPtr<T>(ptr); } template<typename T> inline typename OwnPtr<T>::PtrType OwnPtr<T>::leakPtr() { PtrType ptr = m_ptr; m_ptr = 0; return ptr; } template<typename T> inline typename OwnPtr<T>::ValueType& OwnPtr<T>::operator[](std::ptrdiff_t i) const { COMPILE_ASSERT(IsArray<T>::value, Elements_access_is_possible_for_arrays_only); ASSERT(m_ptr); ASSERT(i >= 0); return m_ptr[i]; } template<typename T> inline OwnPtr<T>& OwnPtr<T>::operator=(const PassOwnPtr<T>& o) { PtrType ptr = m_ptr; m_ptr = o.leakPtr(); ASSERT(!ptr || m_ptr != ptr); OwnedPtrDeleter<T>::deletePtr(ptr); return *this; } template<typename T> template<typename U> inline OwnPtr<T>& OwnPtr<T>::operator=(const PassOwnPtr<U>& o) { COMPILE_ASSERT(!IsArray<T>::value, Pointers_to_array_must_never_be_converted); PtrType ptr = m_ptr; m_ptr = o.leakPtr(); ASSERT(!ptr || m_ptr != ptr); OwnedPtrDeleter<T>::deletePtr(ptr); return *this; } #if COMPILER_SUPPORTS(CXX_RVALUE_REFERENCES) template<typename T> inline OwnPtr<T>::OwnPtr(OwnPtr<T>&& o) : m_ptr(o.leakPtr()) { } template<typename T> template<typename U> inline OwnPtr<T>::OwnPtr(OwnPtr<U>&& o) : m_ptr(o.leakPtr()) { COMPILE_ASSERT(!IsArray<T>::value, Pointers_to_array_must_never_be_converted); } template<typename T> inline OwnPtr<T>& OwnPtr<T>::operator=(OwnPtr<T>&& o) { PtrType ptr = m_ptr; m_ptr = o.leakPtr(); ASSERT(!ptr || m_ptr != ptr); OwnedPtrDeleter<T>::deletePtr(ptr); return *this; } template<typename T> template<typename U> inline OwnPtr<T>& OwnPtr<T>::operator=(OwnPtr<U>&& o) { COMPILE_ASSERT(!IsArray<T>::value, Pointers_to_array_must_never_be_converted); PtrType ptr = m_ptr; m_ptr = o.leakPtr(); ASSERT(!ptr || m_ptr != ptr); OwnedPtrDeleter<T>::deletePtr(ptr); return *this; } #endif template<typename T> inline void swap(OwnPtr<T>& a, OwnPtr<T>& b) { a.swap(b); } template<typename T, typename U> inline bool operator==(const OwnPtr<T>& a, U* b) { return a.get() == b; } template<typename T, typename U> inline bool operator==(T* a, const OwnPtr<U>& b) { return a == b.get(); } template<typename T, typename U> inline bool operator!=(const OwnPtr<T>& a, U* b) { return a.get() != b; } template<typename T, typename U> inline bool operator!=(T* a, const OwnPtr<U>& b) { return a != b.get(); } template<typename T> inline typename OwnPtr<T>::PtrType getPtr(const OwnPtr<T>& p) { return p.get(); } } // namespace WTF using WTF::OwnPtr; #endif // WTF_OwnPtr_h