summaryrefslogtreecommitdiffstats
path: root/Source/JavaScriptCore/wtf/OwnPtr.h
blob: fb594321b5a0543870f8682eb8bd531cb508363b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
/*
 *  Copyright (C) 2006, 2007, 2008, 2009, 2010 Apple Inc. 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 "Assertions.h"
#include "NullPtr.h"
#include "OwnPtrCommon.h"
#include "TypeTraits.h"
#include <algorithm>
#include <memory>

// Remove this once we make all WebKit code compatible with stricter rules about OwnPtr.
#define LOOSE_OWN_PTR

namespace WTF {

    // Unlike most of our smart pointers, OwnPtr can take either the pointer type or the pointed-to type.

    template<typename T> class PassOwnPtr;
    template<typename T> PassOwnPtr<T> adoptPtr(T*);

    template<typename T> class OwnPtr {
    public:
        typedef typename RemovePointer<T>::Type ValueType;
        typedef ValueType* PtrType;

        OwnPtr() : m_ptr(0) { }

        // See comment in PassOwnPtr.h for why this takes a const reference.
        template<typename U> OwnPtr(const PassOwnPtr<U>& o);

        // 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<ValueType>&);

        ~OwnPtr() { deleteOwnedPtr(m_ptr); }

        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; }

        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>&);

        void swap(OwnPtr& o) { std::swap(m_ptr, o.m_ptr); }

#ifdef LOOSE_OWN_PTR
        explicit OwnPtr(PtrType ptr) : m_ptr(ptr) { }
        void set(PtrType);
#endif

    private:
        PtrType m_ptr;
    };

    template<typename T> template<typename U> inline OwnPtr<T>::OwnPtr(const PassOwnPtr<U>& o)
        : m_ptr(o.leakPtr())
    {
    }

    template<typename T> inline void OwnPtr<T>::clear()
    {
        PtrType ptr = m_ptr;
        m_ptr = 0;
        deleteOwnedPtr(ptr);
    }

    template<typename T> inline PassOwnPtr<T> OwnPtr<T>::release()
    {
        PtrType ptr = m_ptr;
        m_ptr = 0;
        return adoptPtr(ptr);
    }

    template<typename T> inline typename OwnPtr<T>::PtrType OwnPtr<T>::leakPtr()
    {
        PtrType ptr = m_ptr;
        m_ptr = 0;
        return ptr;
    }

#ifdef LOOSE_OWN_PTR
    template<typename T> inline void OwnPtr<T>::set(PtrType ptr)
    {
        ASSERT(!ptr || m_ptr != ptr);
        PtrType oldPtr = m_ptr;
        m_ptr = ptr;
        deleteOwnedPtr(oldPtr);
    }
#endif

    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);
        deleteOwnedPtr(ptr);
        return *this;
    }

    template<typename T> template<typename U> inline OwnPtr<T>& OwnPtr<T>::operator=(const PassOwnPtr<U>& o)
    {
        PtrType ptr = m_ptr;
        m_ptr = o.leakPtr();
        ASSERT(!ptr || m_ptr != ptr);
        deleteOwnedPtr(ptr);
        return *this;
    }

    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