1 /* 2 * Copyright (C) 2006, 2007, 2008, 2009 Apple Inc. All rights reserved. 3 * 4 * This library is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU Library General Public 6 * License as published by the Free Software Foundation; either 7 * version 2 of the License, or (at your option) any later version. 8 * 9 * This library is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * Library General Public License for more details. 13 * 14 * You should have received a copy of the GNU Library General Public License 15 * along with this library; see the file COPYING.LIB. If not, write to 16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 17 * Boston, MA 02110-1301, USA. 18 * 19 */ 20 21 #ifndef WTF_OwnPtr_h 22 #define WTF_OwnPtr_h 23 24 #include "Assertions.h" 25 #include "Noncopyable.h" 26 #include "OwnPtrCommon.h" 27 #include "TypeTraits.h" 28 #include <algorithm> 29 #include <memory> 30 31 namespace WTF { 32 33 // Unlike most of our smart pointers, OwnPtr can take either the pointer type or the pointed-to type. 34 35 template <typename T> class PassOwnPtr; 36 37 template <typename T> class OwnPtr : public Noncopyable { 38 public: 39 typedef typename RemovePointer<T>::Type ValueType; 40 typedef ValueType* PtrType; 41 m_ptr(ptr)42 explicit OwnPtr(PtrType ptr = 0) : m_ptr(ptr) { } OwnPtr(std::auto_ptr<ValueType> autoPtr)43 OwnPtr(std::auto_ptr<ValueType> autoPtr) : m_ptr(autoPtr.release()) { } 44 // See comment in PassOwnPtr.h for why this takes a const reference. 45 template <typename U> OwnPtr(const PassOwnPtr<U>& o); 46 47 // This copy constructor is used implicitly by gcc when it generates 48 // transients for assigning a PassOwnPtr<T> object to a stack-allocated 49 // OwnPtr<T> object. It should never be called explicitly and gcc 50 // should optimize away the constructor when generating code. 51 OwnPtr(const OwnPtr<ValueType>& o); 52 ~OwnPtr()53 ~OwnPtr() { deleteOwnedPtr(m_ptr); } 54 get()55 PtrType get() const { return m_ptr; } release()56 PtrType release() { PtrType ptr = m_ptr; m_ptr = 0; return ptr; } 57 58 // FIXME: This should be renamed to adopt. set(PtrType ptr)59 void set(PtrType ptr) { ASSERT(!ptr || m_ptr != ptr); deleteOwnedPtr(m_ptr); m_ptr = ptr; } 60 adopt(std::auto_ptr<ValueType> autoPtr)61 void adopt(std::auto_ptr<ValueType> autoPtr) { ASSERT(!autoPtr.get() || m_ptr != autoPtr.get()); deleteOwnedPtr(m_ptr); m_ptr = autoPtr.release(); } 62 clear()63 void clear() { deleteOwnedPtr(m_ptr); m_ptr = 0; } 64 65 ValueType& operator*() const { ASSERT(m_ptr); return *m_ptr; } 66 PtrType operator->() const { ASSERT(m_ptr); return m_ptr; } 67 68 bool operator!() const { return !m_ptr; } 69 70 // This conversion operator allows implicit conversion to bool but not to other integer types. 71 typedef PtrType OwnPtr::*UnspecifiedBoolType; UnspecifiedBoolType()72 operator UnspecifiedBoolType() const { return m_ptr ? &OwnPtr::m_ptr : 0; } 73 74 OwnPtr& operator=(const PassOwnPtr<T>&); 75 template <typename U> OwnPtr& operator=(const PassOwnPtr<U>&); 76 swap(OwnPtr & o)77 void swap(OwnPtr& o) { std::swap(m_ptr, o.m_ptr); } 78 79 private: 80 PtrType m_ptr; 81 }; 82 OwnPtr(const PassOwnPtr<U> & o)83 template <typename T> template <typename U> inline OwnPtr<T>::OwnPtr(const PassOwnPtr<U>& o) 84 : m_ptr(o.release()) 85 { 86 } 87 88 template <typename T> inline OwnPtr<T>& OwnPtr<T>::operator=(const PassOwnPtr<T>& o) 89 { 90 T* ptr = m_ptr; 91 m_ptr = o.release(); 92 ASSERT(!ptr || m_ptr != ptr); 93 if (ptr) 94 deleteOwnedPtr(ptr); 95 return *this; 96 } 97 98 template <typename T> template <typename U> inline OwnPtr<T>& OwnPtr<T>::operator=(const PassOwnPtr<U>& o) 99 { 100 T* ptr = m_ptr; 101 m_ptr = o.release(); 102 ASSERT(!ptr || m_ptr != ptr); 103 if (ptr) 104 deleteOwnedPtr(ptr); 105 return *this; 106 } 107 swap(OwnPtr<T> & a,OwnPtr<T> & b)108 template <typename T> inline void swap(OwnPtr<T>& a, OwnPtr<T>& b) 109 { 110 a.swap(b); 111 } 112 113 template <typename T, typename U> inline bool operator==(const OwnPtr<T>& a, U* b) 114 { 115 return a.get() == b; 116 } 117 118 template <typename T, typename U> inline bool operator==(T* a, const OwnPtr<U>& b) 119 { 120 return a == b.get(); 121 } 122 123 template <typename T, typename U> inline bool operator!=(const OwnPtr<T>& a, U* b) 124 { 125 return a.get() != b; 126 } 127 128 template <typename T, typename U> inline bool operator!=(T* a, const OwnPtr<U>& b) 129 { 130 return a != b.get(); 131 } 132 getPtr(const OwnPtr<T> & p)133 template <typename T> inline typename OwnPtr<T>::PtrType getPtr(const OwnPtr<T>& p) 134 { 135 return p.get(); 136 } 137 138 } // namespace WTF 139 140 using WTF::OwnPtr; 141 142 #endif // WTF_OwnPtr_h 143