wtf/OwnArrayPtr.h

   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
  30 namespace WTF {
  31
  32 template<typename T> class PassOwnArrayPtr;
  33 template<typename T> PassOwnArrayPtr<T> adoptArrayPtr(T*);
  34
  35 template <typename T> class OwnArrayPtr {
  36 public:
  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
  84 private:
  85     PtrType m_ptr;
  86 };
  87
  88 template<typename T> template<typename U> inline OwnArrayPtr<T>::OwnArrayPtr(const PassOwnArrayPtr<U>& o)
  89     : m_ptr(o.leakPtr())
  90 {
  91 }
  92
  93 template<typename T> inline void OwnArrayPtr<T>::clear()
  94 {
  95     PtrType ptr = m_ptr;
  96     m_ptr = 0;
  97     deleteOwnedArrayPtr(ptr);
  98 }
  99
 100 template<typename T> inline PassOwnArrayPtr<T> OwnArrayPtr<T>::release()
 101 {
 102     PtrType ptr = m_ptr;
 103     m_ptr = 0;
 104     return adoptArrayPtr(ptr);
 105 }
 106
 107 template<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
 115 template<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
 124 template<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
 133 template<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
 142 template <typename T> inline void swap(OwnArrayPtr<T>& a, OwnArrayPtr<T>& b)
 143 {
 144     a.swap(b);
 145 }
 146
 147 template<typename T, typename U> inline bool operator==(const OwnArrayPtr<T>& a, U* b)
 148 {
 149     return a.get() == b;
 150 }
 151
 152 template<typename T, typename U> inline bool operator==(T* a, const OwnArrayPtr<U>& b)
 153 {
 154     return a == b.get();
 155 }
 156
 157 template<typename T, typename U> inline bool operator!=(const OwnArrayPtr<T>& a, U* b)
 158 {
 159     return a.get() != b;
 160 }
 161
 162 template<typename T, typename U> inline bool operator!=(T* a, const OwnArrayPtr<U>& b)
 163 {
 164     return a != b.get();
 165 }
 166
 167 template <typename T> inline T* getPtr(const OwnArrayPtr<T>& p)
 168 {
 169     return p.get();
 170 }
 171
 172 } // namespace WTF
 173
 174 using WTF::OwnArrayPtr;
 175
 176 #endif // WTF_OwnArrayPtr_h