• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  *  Copyright (C) 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
3  *  Copyright (C) 2013 Intel Corporation. All rights reserved.
4  *
5  *  This library is free software; you can redistribute it and/or
6  *  modify it under the terms of the GNU Library General Public
7  *  License as published by the Free Software Foundation; either
8  *  version 2 of the License, or (at your option) any later version.
9  *
10  *  This library is distributed in the hope that it will be useful,
11  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
12  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  *  Library General Public License for more details.
14  *
15  *  You should have received a copy of the GNU Library General Public License
16  *  along with this library; see the file COPYING.LIB.  If not, write to
17  *  the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
18  *  Boston, MA 02110-1301, USA.
19  *
20  */
21 
22 #ifndef WTF_OwnPtr_h
23 #define WTF_OwnPtr_h
24 
25 #include "wtf/Noncopyable.h"
26 #include "wtf/NullPtr.h"
27 #include "wtf/OwnPtrCommon.h"
28 #include <algorithm>
29 
30 namespace WTF {
31 
32     template<typename T> class PassOwnPtr;
33 
34     template<typename T> class OwnPtr {
35 #if COMPILER_SUPPORTS(CXX_RVALUE_REFERENCES)
36         // If rvalue references are not supported, the copy constructor is
37         // public so OwnPtr cannot be marked noncopyable. See note below.
38         WTF_MAKE_NONCOPYABLE(OwnPtr);
39 #endif
40         WTF_DISALLOW_CONSTRUCTION_FROM_ZERO(OwnPtr);
41     public:
42         typedef typename RemoveExtent<T>::Type ValueType;
43         typedef ValueType* PtrType;
44 
OwnPtr()45         OwnPtr() : m_ptr(0) { }
OwnPtr(std::nullptr_t)46         OwnPtr(std::nullptr_t) : m_ptr(0) { }
47 
48         // See comment in PassOwnPtr.h for why this takes a const reference.
49         OwnPtr(const PassOwnPtr<T>&);
50         template<typename U> OwnPtr(const PassOwnPtr<U>&, EnsurePtrConvertibleArgDecl(U, T));
51 
52 #if !COMPILER_SUPPORTS(CXX_RVALUE_REFERENCES)
53         // This copy constructor is used implicitly by gcc when it generates
54         // transients for assigning a PassOwnPtr<T> object to a stack-allocated
55         // OwnPtr<T> object. It should never be called explicitly and gcc
56         // should optimize away the constructor when generating code.
57         OwnPtr(const OwnPtr&);
58 #endif
59 
~OwnPtr()60         ~OwnPtr()
61         {
62             OwnedPtrDeleter<T>::deletePtr(m_ptr);
63             m_ptr = 0;
64         }
65 
get()66         PtrType get() const { return m_ptr; }
67 
68         void clear();
69         PassOwnPtr<T> release();
70         PtrType leakPtr() WARN_UNUSED_RETURN;
71 
72         ValueType& operator*() const { ASSERT(m_ptr); return *m_ptr; }
73         PtrType operator->() const { ASSERT(m_ptr); return m_ptr; }
74 
75         ValueType& operator[](std::ptrdiff_t i) const;
76 
77         bool operator!() const { return !m_ptr; }
78 
79         // This conversion operator allows implicit conversion to bool but not to other integer types.
80         typedef PtrType OwnPtr::*UnspecifiedBoolType;
UnspecifiedBoolType()81         operator UnspecifiedBoolType() const { return m_ptr ? &OwnPtr::m_ptr : 0; }
82 
83         OwnPtr& operator=(const PassOwnPtr<T>&);
84         OwnPtr& operator=(std::nullptr_t) { clear(); return *this; }
85         template<typename U> OwnPtr& operator=(const PassOwnPtr<U>&);
86 
87 #if COMPILER_SUPPORTS(CXX_RVALUE_REFERENCES)
88         OwnPtr(OwnPtr&&);
89         template<typename U> OwnPtr(OwnPtr<U>&&);
90 
91         OwnPtr& operator=(OwnPtr&&);
92         template<typename U> OwnPtr& operator=(OwnPtr<U>&&);
93 #endif
94 
swap(OwnPtr & o)95         void swap(OwnPtr& o) { std::swap(m_ptr, o.m_ptr); }
96 
97     private:
98 #if !COMPILER_SUPPORTS(CXX_RVALUE_REFERENCES)
99         // If rvalue references are supported, noncopyable takes care of this.
100         OwnPtr& operator=(const OwnPtr&);
101 #endif
102 
103         // We should never have two OwnPtrs for the same underlying object (otherwise we'll get
104         // double-destruction), so these equality operators should never be needed.
105         template<typename U> bool operator==(const OwnPtr<U>&) const { COMPILE_ASSERT(!sizeof(U*), OwnPtrs_should_never_be_equal); return false; }
106         template<typename U> bool operator!=(const OwnPtr<U>&) const { COMPILE_ASSERT(!sizeof(U*), OwnPtrs_should_never_be_equal); return false; }
107         template<typename U> bool operator==(const PassOwnPtr<U>&) const { COMPILE_ASSERT(!sizeof(U*), OwnPtrs_should_never_be_equal); return false; }
108         template<typename U> bool operator!=(const PassOwnPtr<U>&) const { COMPILE_ASSERT(!sizeof(U*), OwnPtrs_should_never_be_equal); return false; }
109 
110         PtrType m_ptr;
111     };
112 
OwnPtr(const PassOwnPtr<T> & o)113     template<typename T> inline OwnPtr<T>::OwnPtr(const PassOwnPtr<T>& o)
114         : m_ptr(o.leakPtr())
115     {
116     }
117 
OwnPtr(const PassOwnPtr<U> & o,EnsurePtrConvertibleArgDefn (U,T))118     template<typename T> template<typename U> inline OwnPtr<T>::OwnPtr(const PassOwnPtr<U>& o, EnsurePtrConvertibleArgDefn(U, T))
119         : m_ptr(o.leakPtr())
120     {
121         COMPILE_ASSERT(!IsArray<T>::value, Pointers_to_array_must_never_be_converted);
122     }
123 
clear()124     template<typename T> inline void OwnPtr<T>::clear()
125     {
126         PtrType ptr = m_ptr;
127         m_ptr = 0;
128         OwnedPtrDeleter<T>::deletePtr(ptr);
129     }
130 
release()131     template<typename T> inline PassOwnPtr<T> OwnPtr<T>::release()
132     {
133         PtrType ptr = m_ptr;
134         m_ptr = 0;
135         return PassOwnPtr<T>(ptr);
136     }
137 
leakPtr()138     template<typename T> inline typename OwnPtr<T>::PtrType OwnPtr<T>::leakPtr()
139     {
140         PtrType ptr = m_ptr;
141         m_ptr = 0;
142         return ptr;
143     }
144 
145     template<typename T> inline typename OwnPtr<T>::ValueType& OwnPtr<T>::operator[](std::ptrdiff_t i) const
146     {
147         COMPILE_ASSERT(IsArray<T>::value, Elements_access_is_possible_for_arrays_only);
148         ASSERT(m_ptr);
149         ASSERT(i >= 0);
150         return m_ptr[i];
151     }
152 
153     template<typename T> inline OwnPtr<T>& OwnPtr<T>::operator=(const PassOwnPtr<T>& o)
154     {
155         PtrType ptr = m_ptr;
156         m_ptr = o.leakPtr();
157         ASSERT(!ptr || m_ptr != ptr);
158         OwnedPtrDeleter<T>::deletePtr(ptr);
159         return *this;
160     }
161 
162     template<typename T> template<typename U> inline OwnPtr<T>& OwnPtr<T>::operator=(const PassOwnPtr<U>& o)
163     {
164         COMPILE_ASSERT(!IsArray<T>::value, Pointers_to_array_must_never_be_converted);
165         PtrType ptr = m_ptr;
166         m_ptr = o.leakPtr();
167         ASSERT(!ptr || m_ptr != ptr);
168         OwnedPtrDeleter<T>::deletePtr(ptr);
169         return *this;
170     }
171 
172 #if COMPILER_SUPPORTS(CXX_RVALUE_REFERENCES)
OwnPtr(OwnPtr<T> && o)173     template<typename T> inline OwnPtr<T>::OwnPtr(OwnPtr<T>&& o)
174         : m_ptr(o.leakPtr())
175     {
176     }
177 
OwnPtr(OwnPtr<U> && o)178     template<typename T> template<typename U> inline OwnPtr<T>::OwnPtr(OwnPtr<U>&& o)
179         : m_ptr(o.leakPtr())
180     {
181         COMPILE_ASSERT(!IsArray<T>::value, Pointers_to_array_must_never_be_converted);
182     }
183 
184     template<typename T> inline OwnPtr<T>& OwnPtr<T>::operator=(OwnPtr<T>&& o)
185     {
186         PtrType ptr = m_ptr;
187         m_ptr = o.leakPtr();
188         ASSERT(!ptr || m_ptr != ptr);
189         OwnedPtrDeleter<T>::deletePtr(ptr);
190 
191         return *this;
192     }
193 
194     template<typename T> template<typename U> inline OwnPtr<T>& OwnPtr<T>::operator=(OwnPtr<U>&& o)
195     {
196         COMPILE_ASSERT(!IsArray<T>::value, Pointers_to_array_must_never_be_converted);
197         PtrType ptr = m_ptr;
198         m_ptr = o.leakPtr();
199         ASSERT(!ptr || m_ptr != ptr);
200         OwnedPtrDeleter<T>::deletePtr(ptr);
201 
202         return *this;
203     }
204 #endif
205 
swap(OwnPtr<T> & a,OwnPtr<T> & b)206     template<typename T> inline void swap(OwnPtr<T>& a, OwnPtr<T>& b)
207     {
208         a.swap(b);
209     }
210 
211     template<typename T, typename U> inline bool operator==(const OwnPtr<T>& a, U* b)
212     {
213         return a.get() == b;
214     }
215 
216     template<typename T, typename U> inline bool operator==(T* a, const OwnPtr<U>& b)
217     {
218         return a == b.get();
219     }
220 
221     template<typename T, typename U> inline bool operator!=(const OwnPtr<T>& a, U* b)
222     {
223         return a.get() != b;
224     }
225 
226     template<typename T, typename U> inline bool operator!=(T* a, const OwnPtr<U>& b)
227     {
228         return a != b.get();
229     }
230 
getPtr(const OwnPtr<T> & p)231     template<typename T> inline typename OwnPtr<T>::PtrType getPtr(const OwnPtr<T>& p)
232     {
233         return p.get();
234     }
235 
236 } // namespace WTF
237 
238 using WTF::OwnPtr;
239 
240 #endif // WTF_OwnPtr_h
241