WebCore/DocPtr.h

   1 /*
   2  * This file is part of the DOM implementation for KDE.
   3  * Copyright (C) 2005, 2006 Apple Computer, Inc.
   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 DocPtr_h
  23 #define DocPtr_h
  24
  25 namespace WebCore {
  26
  27 template <class T> class DocPtr {
  28 public:
  29     DocPtr() : m_ptr(0) {}
  30     DocPtr(T *ptr) : m_ptr(ptr) { if (ptr) ptr->selfOnlyRef(); }
  31     DocPtr(const DocPtr &o) : m_ptr(o.m_ptr) { if (T *ptr = m_ptr) ptr->selfOnlyRef(); }
  32     ~DocPtr() { if (T *ptr = m_ptr) ptr->selfOnlyDeref(); }
  33
  34     template <class U> DocPtr(const DocPtr<U> &o) : m_ptr(o.get()) { if (T *ptr = m_ptr) ptr->selfOnlyRef(); }
  35
  36     void resetSkippingRef(T *o) { m_ptr = o; }
  37
  38     T *get() const { return m_ptr; }
  39
  40     T &operator*() const { return *m_ptr; }
  41     T *operator->() const { return m_ptr; }
  42
  43     bool operator!() const { return !m_ptr; }
  44
  45     // this type conversion operator allows implicit conversion to
  46     // bool but not to other integer types
  47
  48     typedef T * (DocPtr::*UnspecifiedBoolType)() const;
  49     operator UnspecifiedBoolType() const
  50     {
  51         return m_ptr ? &DocPtr::get : 0;
  52     }
  53
  54     DocPtr &operator=(const DocPtr &);
  55     DocPtr &operator=(T *);
  56
  57  private:
  58     T *m_ptr;
  59 };
  60
  61 template <class T> DocPtr<T> &DocPtr<T>::operator=(const DocPtr<T> &o)
  62 {
  63     T *optr = o.m_ptr;
  64     if (optr)
  65         optr->selfOnlyRef();
  66     if (T *ptr = m_ptr)
  67         ptr->selfOnlyDeref();
  68     m_ptr = optr;
  69         return *this;
  70 }
  71
  72 template <class T> inline DocPtr<T> &DocPtr<T>::operator=(T *optr)
  73 {
  74     if (optr)
  75         optr->selfOnlyRef();
  76     if (T *ptr = m_ptr)
  77         ptr->selfOnlyDeref();
  78     m_ptr = optr;
  79     return *this;
  80 }
  81
  82 template <class T> inline bool operator==(const DocPtr<T> &a, const DocPtr<T> &b)
  83 {
  84     return a.get() == b.get();
  85 }
  86
  87 template <class T> inline bool operator==(const DocPtr<T> &a, const T *b)
  88 {
  89     return a.get() == b;
  90 }
  91
  92 template <class T> inline bool operator==(const T *a, const DocPtr<T> &b)
  93 {
  94     return a == b.get();
  95 }
  96
  97 template <class T> inline bool operator!=(const DocPtr<T> &a, const DocPtr<T> &b)
  98 {
  99     return a.get() != b.get();
 100 }
 101
 102 template <class T> inline bool operator!=(const DocPtr<T> &a, const T *b)
 103 {
 104     return a.get() != b;
 105 }
 106
 107 template <class T> inline bool operator!=(const T *a, const DocPtr<T> &b)
 108 {
 109     return a != b.get();
 110 }
 111
 112 } // namespace WebCore
 113
 114 #endif // DocPtr_h