2 * Copyright (C) 2009, 2010 Apple Inc. All rights reserved.
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 #ifndef WTF_PassOwnPtr_h
27 #define WTF_PassOwnPtr_h
29 #include "Assertions.h"
31 #include "OwnPtrCommon.h"
32 #include "TypeTraits.h"
36 // Unlike most of our smart pointers, PassOwnPtr can take either the pointer type or the pointed-to type.
38 template<typename T> class OwnPtr;
39 template<typename T> class PassOwnPtr;
40 template<typename T> PassOwnPtr<T> adoptPtr(T*);
42 template<typename T> class PassOwnPtr {
44 typedef typename RemovePointer<T>::Type ValueType;
45 typedef ValueType* PtrType;
47 PassOwnPtr() : m_ptr(0) { }
48 PassOwnPtr(std::nullptr_t) : m_ptr(0) { }
50 // It somewhat breaks the type system to allow transfer of ownership out of
51 // a const PassOwnPtr. However, it makes it much easier to work with PassOwnPtr
52 // temporaries, and we don't have a need to use real const PassOwnPtrs anyway.
53 PassOwnPtr(const PassOwnPtr& o) : m_ptr(o.leakPtr()) { }
54 template<typename U> PassOwnPtr(const PassOwnPtr<U>& o) : m_ptr(o.leakPtr()) { }
56 ~PassOwnPtr() { deleteOwnedPtr(m_ptr); }
58 PtrType get() const { return m_ptr; }
60 PtrType leakPtr() const WARN_UNUSED_RETURN;
62 ValueType& operator*() const { ASSERT(m_ptr); return *m_ptr; }
63 PtrType operator->() const { ASSERT(m_ptr); return m_ptr; }
65 bool operator!() const { return !m_ptr; }
67 // This conversion operator allows implicit conversion to bool but not to other integer types.
68 typedef PtrType PassOwnPtr::*UnspecifiedBoolType;
69 operator UnspecifiedBoolType() const { return m_ptr ? &PassOwnPtr::m_ptr : 0; }
71 PassOwnPtr& operator=(const PassOwnPtr&) { COMPILE_ASSERT(!sizeof(T*), PassOwnPtr_should_never_be_assigned_to); return *this; }
73 template<typename U> friend PassOwnPtr<U> adoptPtr(U*);
76 explicit PassOwnPtr(PtrType ptr) : m_ptr(ptr) { }
78 // We should never have two OwnPtrs for the same underlying object (otherwise we'll get
79 // double-destruction), so these equality operators should never be needed.
80 template<typename U> bool operator==(const PassOwnPtr<U>&) { COMPILE_ASSERT(!sizeof(U*), OwnPtrs_should_never_be_equal); return false; }
81 template<typename U> bool operator!=(const PassOwnPtr<U>&) { COMPILE_ASSERT(!sizeof(U*), OwnPtrs_should_never_be_equal); return false; }
82 template<typename U> bool operator==(const OwnPtr<U>&) { COMPILE_ASSERT(!sizeof(U*), OwnPtrs_should_never_be_equal); return false; }
83 template<typename U> bool operator!=(const OwnPtr<U>&) { COMPILE_ASSERT(!sizeof(U*), OwnPtrs_should_never_be_equal); return false; }
85 mutable PtrType m_ptr;
88 template<typename T> inline typename PassOwnPtr<T>::PtrType PassOwnPtr<T>::leakPtr() const
95 template<typename T, typename U> inline bool operator==(const PassOwnPtr<T>& a, const PassOwnPtr<U>& b)
97 return a.get() == b.get();
100 template<typename T, typename U> inline bool operator==(const PassOwnPtr<T>& a, const OwnPtr<U>& b)
102 return a.get() == b.get();
105 template<typename T, typename U> inline bool operator==(const OwnPtr<T>& a, const PassOwnPtr<U>& b)
107 return a.get() == b.get();
110 template<typename T, typename U> inline bool operator==(const PassOwnPtr<T>& a, U* b)
115 template<typename T, typename U> inline bool operator==(T* a, const PassOwnPtr<U>& b)
120 template<typename T, typename U> inline bool operator!=(const PassOwnPtr<T>& a, const PassOwnPtr<U>& b)
122 return a.get() != b.get();
125 template<typename T, typename U> inline bool operator!=(const PassOwnPtr<T>& a, const OwnPtr<U>& b)
127 return a.get() != b.get();
130 template<typename T, typename U> inline bool operator!=(const OwnPtr<T>& a, const PassOwnPtr<U>& b)
132 return a.get() != b.get();
135 template<typename T, typename U> inline bool operator!=(const PassOwnPtr<T>& a, U* b)
140 template<typename T, typename U> inline bool operator!=(T* a, const PassOwnPtr<U>& b)
145 template<typename T> inline PassOwnPtr<T> adoptPtr(T* ptr)
147 return PassOwnPtr<T>(ptr);
150 template<typename T, typename U> inline PassOwnPtr<T> static_pointer_cast(const PassOwnPtr<U>& p)
152 return adoptPtr(static_cast<T*>(p.leakPtr()));
155 template<typename T, typename U> inline PassOwnPtr<T> const_pointer_cast(const PassOwnPtr<U>& p)
157 return adoptPtr(const_cast<T*>(p.leakPtr()));
160 template<typename T> inline T* getPtr(const PassOwnPtr<T>& p)
167 using WTF::PassOwnPtr;
169 using WTF::const_pointer_cast;
170 using WTF::static_pointer_cast;
172 #endif // WTF_PassOwnPtr_h