1/*
2 *  Copyright (C) 2006, 2010 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_OwnArrayPtr_h
22#define WTF_OwnArrayPtr_h
23
24#include "Assertions.h"
25#include "Noncopyable.h"
26#include "NullPtr.h"
27#include "PassOwnArrayPtr.h"
28#include <algorithm>
29
30namespace WTF {
31
32template<typename T> class PassOwnArrayPtr;
33template<typename T> PassOwnArrayPtr<T> adoptArrayPtr(T*);
34
35template <typename T> class OwnArrayPtr {
36public:
37    typedef T* PtrType;
38
39    OwnArrayPtr() : m_ptr(0) { }
40
41    // See comment in PassOwnArrayPtr.h for why this takes a const reference.
42    template<typename U> OwnArrayPtr(const PassOwnArrayPtr<U>& o);
43
44    // This copy constructor is used implicitly by gcc when it generates
45    // transients for assigning a PassOwnArrayPtr<T> object to a stack-allocated
46    // OwnArrayPtr<T> object. It should never be called explicitly and gcc
47    // should optimize away the constructor when generating code.
48    OwnArrayPtr(const OwnArrayPtr<T>&);
49
50    ~OwnArrayPtr() { deleteOwnedArrayPtr(m_ptr); }
51
52    PtrType get() const { return m_ptr; }
53
54    void clear();
55    PassOwnArrayPtr<T> release();
56    PtrType leakPtr() WARN_UNUSED_RETURN;
57
58    T& operator*() const { ASSERT(m_ptr); return *m_ptr; }
59    PtrType operator->() const { ASSERT(m_ptr); return m_ptr; }
60
61    T& operator[](std::ptrdiff_t i) const { ASSERT(m_ptr); ASSERT(i >= 0); return m_ptr[i]; }
62
63    bool operator!() const { return !m_ptr; }
64
65    // This conversion operator allows implicit conversion to bool but not to other integer types.
66#if COMPILER(WINSCW)
67    operator bool() const { return m_ptr; }
68#else
69    typedef T* OwnArrayPtr::*UnspecifiedBoolType;
70    operator UnspecifiedBoolType() const { return m_ptr ? &OwnArrayPtr::m_ptr : 0; }
71#endif
72
73    OwnArrayPtr& operator=(const PassOwnArrayPtr<T>&);
74    OwnArrayPtr& operator=(std::nullptr_t) { clear(); return *this; }
75    template<typename U> OwnArrayPtr& operator=(const PassOwnArrayPtr<U>&);
76
77    void swap(OwnArrayPtr& o) { std::swap(m_ptr, o.m_ptr); }
78
79#ifdef LOOSE_OWN_ARRAY_PTR
80    explicit OwnArrayPtr(PtrType ptr) : m_ptr(ptr) { }
81    void set(PtrType);
82#endif
83
84private:
85    PtrType m_ptr;
86};
87
88template<typename T> template<typename U> inline OwnArrayPtr<T>::OwnArrayPtr(const PassOwnArrayPtr<U>& o)
89    : m_ptr(o.leakPtr())
90{
91}
92
93template<typename T> inline void OwnArrayPtr<T>::clear()
94{
95    PtrType ptr = m_ptr;
96    m_ptr = 0;
97    deleteOwnedArrayPtr(ptr);
98}
99
100template<typename T> inline PassOwnArrayPtr<T> OwnArrayPtr<T>::release()
101{
102    PtrType ptr = m_ptr;
103    m_ptr = 0;
104    return adoptArrayPtr(ptr);
105}
106
107template<typename T> inline typename OwnArrayPtr<T>::PtrType OwnArrayPtr<T>::leakPtr()
108{
109    PtrType ptr = m_ptr;
110    m_ptr = 0;
111    return ptr;
112}
113
114#ifdef LOOSE_OWN_ARRAY_PTR
115template<typename T> inline void OwnArrayPtr<T>::set(PtrType ptr)
116{
117    ASSERT(!ptr || m_ptr != ptr);
118    PtrType oldPtr = m_ptr;
119    m_ptr = ptr;
120    deleteOwnedArrayPtr(oldPtr);
121}
122#endif
123
124template<typename T> inline OwnArrayPtr<T>& OwnArrayPtr<T>::operator=(const PassOwnArrayPtr<T>& o)
125{
126    PtrType ptr = m_ptr;
127    m_ptr = o.leakPtr();
128    ASSERT(!ptr || m_ptr != ptr);
129    deleteOwnedArrayPtr(ptr);
130    return *this;
131}
132
133template<typename T> template<typename U> inline OwnArrayPtr<T>& OwnArrayPtr<T>::operator=(const PassOwnArrayPtr<U>& o)
134{
135    PtrType ptr = m_ptr;
136    m_ptr = o.leakPtr();
137    ASSERT(!ptr || m_ptr != ptr);
138    deleteOwnedArrayPtr(ptr);
139    return *this;
140}
141
142template <typename T> inline void swap(OwnArrayPtr<T>& a, OwnArrayPtr<T>& b)
143{
144    a.swap(b);
145}
146
147template<typename T, typename U> inline bool operator==(const OwnArrayPtr<T>& a, U* b)
148{
149    return a.get() == b;
150}
151
152template<typename T, typename U> inline bool operator==(T* a, const OwnArrayPtr<U>& b)
153{
154    return a == b.get();
155}
156
157template<typename T, typename U> inline bool operator!=(const OwnArrayPtr<T>& a, U* b)
158{
159    return a.get() != b;
160}
161
162template<typename T, typename U> inline bool operator!=(T* a, const OwnArrayPtr<U>& b)
163{
164    return a != b.get();
165}
166
167template <typename T> inline T* getPtr(const OwnArrayPtr<T>& p)
168{
169    return p.get();
170}
171
172} // namespace WTF
173
174using WTF::OwnArrayPtr;
175
176#endif // WTF_OwnArrayPtr_h
177