1 /*
2 * Copyright (C) 2010 Apple Inc. All rights reserved.
3 *
4 * Redistribution and use in source and binary forms, with or without
5 * modification, are permitted provided that the following conditions
6 * are met:
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.
12 *
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.
24 */
25
26 #ifndef WTF_PassOwnArrayPtr_h
27 #define WTF_PassOwnArrayPtr_h
28
29 #include "Assertions.h"
30 #include "NullPtr.h"
31 #include "TypeTraits.h"
32
33 namespace WTF {
34
35 template<typename T> class OwnArrayPtr;
36 template<typename T> class PassOwnArrayPtr;
37 template<typename T> PassOwnArrayPtr<T> adoptArrayPtr(T*);
38 template<typename T> void deleteOwnedArrayPtr(T* ptr);
39
40 template<typename T> class PassOwnArrayPtr {
41 public:
42 typedef T* PtrType;
43
PassOwnArrayPtr()44 PassOwnArrayPtr() : m_ptr(0) { }
45
46 #if !defined(LOOSE_PASS_OWN_PTR) || !HAVE(NULLPTR)
PassOwnArrayPtr(std::nullptr_t)47 PassOwnArrayPtr(std::nullptr_t) : m_ptr(0) { }
48 #endif
49
50 // It somewhat breaks the type system to allow transfer of ownership out of
51 // a const PassOwnArrayPtr. However, it makes it much easier to work with PassOwnArrayPtr
52 // temporaries, and we don't have a need to use real const PassOwnArrayPtrs anyway.
PassOwnArrayPtr(const PassOwnArrayPtr & o)53 PassOwnArrayPtr(const PassOwnArrayPtr& o) : m_ptr(o.leakPtr()) { }
PassOwnArrayPtr(const PassOwnArrayPtr<U> & o)54 template<typename U> PassOwnArrayPtr(const PassOwnArrayPtr<U>& o) : m_ptr(o.leakPtr()) { }
55
~PassOwnArrayPtr()56 ~PassOwnArrayPtr() { deleteOwnedArrayPtr(m_ptr); }
57
get()58 PtrType get() const { return m_ptr; }
59
60 void clear();
61 PtrType leakPtr() const WARN_UNUSED_RETURN;
62
63 T& operator*() const { ASSERT(m_ptr); return *m_ptr; }
64 PtrType operator->() const { ASSERT(m_ptr); return m_ptr; }
65
66 bool operator!() const { return !m_ptr; }
67
68 // This conversion operator allows implicit conversion to bool but not to other integer types.
69 #if COMPILER(WINSCW)
70 operator bool() const { return m_ptr; }
71 #else
72 typedef PtrType PassOwnArrayPtr::*UnspecifiedBoolType;
UnspecifiedBoolType()73 operator UnspecifiedBoolType() const { return m_ptr ? &PassOwnArrayPtr::m_ptr : 0; }
74 #endif
75
76 PassOwnArrayPtr& operator=(const PassOwnArrayPtr<T>&);
77 #if !defined(LOOSE_PASS_OWN_ARRAY_PTR) || !HAVE(NULLPTR)
78 PassOwnArrayPtr& operator=(std::nullptr_t) { clear(); return *this; }
79 #endif
80 template<typename U> PassOwnArrayPtr& operator=(const PassOwnArrayPtr<U>&);
81
82 template<typename U> friend PassOwnArrayPtr<U> adoptArrayPtr(U*);
83
84 #ifdef LOOSE_PASS_OWN_ARRAY_PTR
PassOwnArrayPtr(PtrType ptr)85 PassOwnArrayPtr(PtrType ptr) : m_ptr(ptr) { }
86 PassOwnArrayPtr& operator=(PtrType);
87 #endif
88
89 private:
90 #ifndef LOOSE_PASS_OWN_ARRAY_PTR
PassOwnArrayPtr(PtrType ptr)91 explicit PassOwnArrayPtr(PtrType ptr) : m_ptr(ptr) { }
92 #endif
93
94 mutable PtrType m_ptr;
95 };
96
clear()97 template<typename T> inline void PassOwnArrayPtr<T>::clear()
98 {
99 PtrType ptr = m_ptr;
100 m_ptr = 0;
101 deleteOwnedArrayPtr(ptr);
102 }
103
leakPtr()104 template<typename T> inline typename PassOwnArrayPtr<T>::PtrType PassOwnArrayPtr<T>::leakPtr() const
105 {
106 PtrType ptr = m_ptr;
107 m_ptr = 0;
108 return ptr;
109 }
110
111 #ifdef LOOSE_PASS_OWN_ARRAY_PTR
112 template<typename T> inline PassOwnArrayPtr<T>& PassOwnArrayPtr<T>::operator=(PtrType optr)
113 {
114 PtrType ptr = m_ptr;
115 m_ptr = optr;
116 ASSERT(!ptr || m_ptr != ptr);
117 if (ptr)
118 deleteOwnedArrayPtr(ptr);
119 return *this;
120 }
121 #endif
122
123 template<typename T> inline PassOwnArrayPtr<T>& PassOwnArrayPtr<T>::operator=(const PassOwnArrayPtr<T>& optr)
124 {
125 PtrType ptr = m_ptr;
126 m_ptr = optr.leakPtr();
127 ASSERT(!ptr || m_ptr != ptr);
128 if (ptr)
129 deleteOwnedArrayPtr(ptr);
130 return *this;
131 }
132
133 template<typename T> template<typename U> inline PassOwnArrayPtr<T>& PassOwnArrayPtr<T>::operator=(const PassOwnArrayPtr<U>& optr)
134 {
135 PtrType ptr = m_ptr;
136 m_ptr = optr.leakPtr();
137 ASSERT(!ptr || m_ptr != ptr);
138 if (ptr)
139 deleteOwnedArrayPtr(ptr);
140 return *this;
141 }
142
143 template<typename T, typename U> inline bool operator==(const PassOwnArrayPtr<T>& a, const PassOwnArrayPtr<U>& b)
144 {
145 return a.get() == b.get();
146 }
147
148 template<typename T, typename U> inline bool operator==(const PassOwnArrayPtr<T>& a, const OwnArrayPtr<U>& b)
149 {
150 return a.get() == b.get();
151 }
152
153 template<typename T, typename U> inline bool operator==(const OwnArrayPtr<T>& a, const PassOwnArrayPtr<U>& b)
154 {
155 return a.get() == b.get();
156 }
157
158 template<typename T, typename U> inline bool operator==(const PassOwnArrayPtr<T>& a, U* b)
159 {
160 return a.get() == b;
161 }
162
163 template<typename T, typename U> inline bool operator==(T* a, const PassOwnArrayPtr<U>& b)
164 {
165 return a == b.get();
166 }
167
168 template<typename T, typename U> inline bool operator!=(const PassOwnArrayPtr<T>& a, const PassOwnArrayPtr<U>& b)
169 {
170 return a.get() != b.get();
171 }
172
173 template<typename T, typename U> inline bool operator!=(const PassOwnArrayPtr<T>& a, const OwnArrayPtr<U>& b)
174 {
175 return a.get() != b.get();
176 }
177
178 template<typename T, typename U> inline bool operator!=(const OwnArrayPtr<T>& a, const PassOwnArrayPtr<U>& b)
179 {
180 return a.get() != b.get();
181 }
182
183 template<typename T, typename U> inline bool operator!=(const PassOwnArrayPtr<T>& a, U* b)
184 {
185 return a.get() != b;
186 }
187
188 template<typename T, typename U> inline bool operator!=(T* a, const PassOwnArrayPtr<U>& b)
189 {
190 return a != b.get();
191 }
192
adoptArrayPtr(T * ptr)193 template<typename T> inline PassOwnArrayPtr<T> adoptArrayPtr(T* ptr)
194 {
195 return PassOwnArrayPtr<T>(ptr);
196 }
197
deleteOwnedArrayPtr(T * ptr)198 template<typename T> inline void deleteOwnedArrayPtr(T* ptr)
199 {
200 typedef char known[sizeof(T) ? 1 : -1];
201 if (sizeof(known))
202 delete [] ptr;
203 }
204
static_pointer_cast(const PassOwnArrayPtr<U> & p)205 template<typename T, typename U> inline PassOwnArrayPtr<T> static_pointer_cast(const PassOwnArrayPtr<U>& p)
206 {
207 return adoptArrayPtr(static_cast<T*>(p.leakPtr()));
208 }
209
const_pointer_cast(const PassOwnArrayPtr<U> & p)210 template<typename T, typename U> inline PassOwnArrayPtr<T> const_pointer_cast(const PassOwnArrayPtr<U>& p)
211 {
212 return adoptArrayPtr(const_cast<T*>(p.leakPtr()));
213 }
214
getPtr(const PassOwnArrayPtr<T> & p)215 template<typename T> inline T* getPtr(const PassOwnArrayPtr<T>& p)
216 {
217 return p.get();
218 }
219
220 } // namespace WTF
221
222 using WTF::PassOwnArrayPtr;
223 using WTF::adoptArrayPtr;
224 using WTF::const_pointer_cast;
225 using WTF::static_pointer_cast;
226
227 #endif // WTF_PassOwnArrayPtr_h
228