interface/wx/sharedptr.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        sharedptr.h
   3 // Purpose:     interface of wxSharedPtr<T>
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows licence
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9 /**
  10     A smart pointer with non-intrusive reference counting.
  11
  12     It is modeled after @c boost::shared_ptr<> and can be used with STL
  13     containers and wxVector<T> unlike @c std::auto_ptr<> and wxScopedPtr<T>.
  14
  15     @library{wxbase}
  16     @category{smartpointers}
  17
  18     @see wxScopedPtr<T>, wxWeakRef<T>, wxObjectDataPtr<T>
  19 */
  20 template<typename T>
  21 class wxSharedPtr<T>
  22 {
  23 public:
  24     /**
  25         Constructor.
  26
  27         Creates shared pointer from the raw pointer @a ptr and takes ownership
  28         of it.
  29     */
  30     wxEXPLICIT wxSharedPtr(T* ptr = NULL);
  31
  32     /**
  33         Copy constructor.
  34     */
  35     wxSharedPtr(const wxSharedPtr<T>& tocopy);
  36
  37     /**
  38         Destructor.
  39     */
  40     ~wxSharedPtr();
  41
  42     /**
  43         Returns pointer to its object or @NULL.
  44     */
  45     T* get() const;
  46
  47     /**
  48         Conversion to a boolean expression (in a variant which is not
  49         convertible to anything but a boolean expression).
  50
  51         If this class contains a valid pointer it will return @true, if it contains
  52         a @NULL pointer it will return @false.
  53     */
  54     operator unspecified_bool_type() const;
  55
  56     /**
  57         Returns a reference to the object.
  58
  59         If the internal pointer is @NULL this method will cause an assert in debug mode.
  60     */
  61     T operator*() const;
  62
  63     /**
  64         Returns pointer to its object or @NULL.
  65     */
  66     T* operator->() const;
  67
  68     /**
  69         Assignment operator.
  70
  71         Releases any previously held pointer and creates a reference to @a ptr.
  72     */
  73     wxSharedPtr<T>& operator=(T* ptr);
  74
  75     /**
  76         Assignment operator.
  77
  78         Releases any previously held pointer and creates a reference to the
  79         same object as @a topcopy.
  80     */
  81     wxSharedPtr<T>& operator=(const wxSharedPtr<T>& tocopy);
  82
  83     /**
  84         Reset pointer to @a ptr.
  85
  86         If the reference count of the previously owned pointer was 1 it will be deleted.
  87     */
  88     void reset(T* ptr = NULL);
  89
  90     /**
  91         Returns @true if this is the only pointer pointing to its object.
  92     */
  93     bool unique() const;
  94
  95     /**
  96         Returns the number of pointers pointing to its object.
  97     */
  98     long use_count() const;
  99 };
 100