API/JSRetainPtr.h

   1 /*
   2  * Copyright (C) 2005, 2006, 2007 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  *
   8  * 1.  Redistributions of source code must retain the above copyright
   9  *     notice, this list of conditions and the following disclaimer.
  10  * 2.  Redistributions in binary form must reproduce the above copyright
  11  *     notice, this list of conditions and the following disclaimer in the
  12  *     documentation and/or other materials provided with the distribution.
  13  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
  14  *     its contributors may be used to endorse or promote products derived
  15  *     from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
  18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
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  22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
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  24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 #ifndef JSRetainPtr_h
  30 #define JSRetainPtr_h
  31
  32 #include <JavaScriptCore/JSStringRef.h>
  33 #include <algorithm>
  34
  35 inline void JSRetain(JSStringRef string) { JSStringRetain(string); }
  36 inline void JSRelease(JSStringRef string) { JSStringRelease(string); }
  37
  38 enum AdoptTag { Adopt };
  39
  40 template <typename T> class JSRetainPtr {
  41 public:
  42     JSRetainPtr() : m_ptr(0) {}
  43     JSRetainPtr(T ptr) : m_ptr(ptr) { if (ptr) JSRetain(ptr); }
  44
  45     JSRetainPtr(AdoptTag, T ptr) : m_ptr(ptr) { }
  46
  47     JSRetainPtr(const JSRetainPtr& o) : m_ptr(o.m_ptr) { if (T ptr = m_ptr) JSRetain(ptr); }
  48
  49     ~JSRetainPtr() { if (T ptr = m_ptr) JSRelease(ptr); }
  50
  51     template <typename U> JSRetainPtr(const JSRetainPtr<U>& o) : m_ptr(o.get()) { if (T ptr = m_ptr) JSRetain(ptr); }
  52
  53     T get() const { return m_ptr; }
  54
  55     T releaseRef() { T tmp = m_ptr; m_ptr = 0; return tmp; }
  56
  57     T operator->() const { return m_ptr; }
  58
  59     bool operator!() const { return !m_ptr; }
  60
  61     // This conversion operator allows implicit conversion to bool but not to other integer types.
  62     typedef T JSRetainPtr::*UnspecifiedBoolType;
  63     operator UnspecifiedBoolType() const { return m_ptr ? &JSRetainPtr::m_ptr : 0; }
  64
  65     JSRetainPtr& operator=(const JSRetainPtr&);
  66     template <typename U> JSRetainPtr& operator=(const JSRetainPtr<U>&);
  67     JSRetainPtr& operator=(T);
  68     template <typename U> JSRetainPtr& operator=(U*);
  69
  70     void adopt(T);
  71
  72     void swap(JSRetainPtr&);
  73
  74 private:
  75     T m_ptr;
  76 };
  77
  78 template <typename T> inline JSRetainPtr<T>& JSRetainPtr<T>::operator=(const JSRetainPtr<T>& o)
  79 {
  80     T optr = o.get();
  81     if (optr)
  82         JSRetain(optr);
  83     T ptr = m_ptr;
  84     m_ptr = optr;
  85     if (ptr)
  86         JSRelease(ptr);
  87     return *this;
  88 }
  89
  90 template <typename T> template <typename U> inline JSRetainPtr<T>& JSRetainPtr<T>::operator=(const JSRetainPtr<U>& o)
  91 {
  92     T optr = o.get();
  93     if (optr)
  94         JSRetain(optr);
  95     T ptr = m_ptr;
  96     m_ptr = optr;
  97     if (ptr)
  98         JSRelease(ptr);
  99     return *this;
 100 }
 101
 102 template <typename T> inline JSRetainPtr<T>& JSRetainPtr<T>::operator=(T optr)
 103 {
 104     if (optr)
 105         JSRetain(optr);
 106     T ptr = m_ptr;
 107     m_ptr = optr;
 108     if (ptr)
 109         JSRelease(ptr);
 110     return *this;
 111 }
 112
 113 template <typename T> inline void JSRetainPtr<T>::adopt(T optr)
 114 {
 115     T ptr = m_ptr;
 116     m_ptr = optr;
 117     if (ptr)
 118         JSRelease(ptr);
 119 }
 120
 121 template <typename T> template <typename U> inline JSRetainPtr<T>& JSRetainPtr<T>::operator=(U* optr)
 122 {
 123     if (optr)
 124         JSRetain(optr);
 125     T ptr = m_ptr;
 126     m_ptr = optr;
 127     if (ptr)
 128         JSRelease(ptr);
 129     return *this;
 130 }
 131
 132 template <class T> inline void JSRetainPtr<T>::swap(JSRetainPtr<T>& o)
 133 {
 134     std::swap(m_ptr, o.m_ptr);
 135 }
 136
 137 template <class T> inline void swap(JSRetainPtr<T>& a, JSRetainPtr<T>& b)
 138 {
 139     a.swap(b);
 140 }
 141
 142 template <typename T, typename U> inline bool operator==(const JSRetainPtr<T>& a, const JSRetainPtr<U>& b)
 143 {
 144     return a.get() == b.get();
 145 }
 146
 147 template <typename T, typename U> inline bool operator==(const JSRetainPtr<T>& a, U* b)
 148 {
 149     return a.get() == b;
 150 }
 151
 152 template <typename T, typename U> inline bool operator==(T* a, const JSRetainPtr<U>& b)
 153 {
 154     return a == b.get();
 155 }
 156
 157 template <typename T, typename U> inline bool operator!=(const JSRetainPtr<T>& a, const JSRetainPtr<U>& b)
 158 {
 159     return a.get() != b.get();
 160 }
 161
 162 template <typename T, typename U> inline bool operator!=(const JSRetainPtr<T>& a, U* b)
 163 {
 164     return a.get() != b;
 165 }
 166
 167 template <typename T, typename U> inline bool operator!=(T* a, const JSRetainPtr<U>& b)
 168 {
 169     return a != b.get();
 170 }
 171
 172
 173 #endif // JSRetainPtr_h