interface/ptr_shrd.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        ptr_shrd.h
   3 // Purpose:     interface of wxSharedPtr<T>
   4 // Author:      wxWidgets team
   5 // RCS-ID:      $Id$
   6 // Licence:     wxWindows license
   7 /////////////////////////////////////////////////////////////////////////////
   8
   9 /**
  10     @wxheader{ptr_shrd.h}
  11
  12     A smart pointer with non-intrusive reference counting. It is modeled after
  13     @c boost::shared_ptr<> and can be used with STL containers and wxVector<T> -
  14     unlike @c std::auto_ptr<> and wxScopedPtr<T>.
  15
  16     @library{wxbase}
  17     @category{smartpointers}
  18
  19     @see wxScopedPtr<T>, wxWeakRef<T>, wxObjectDataPtr<T>
  20 */
  21
  22 template<typename T>
  23 class wxSharedPtr<T>
  24 {
  25 public:
  26     /**
  27         Constructor.
  28
  29         Creates shared pointer from the raw pointer @a ptr and takes ownership
  30         of it.
  31     */
  32     wxEXPLICIT wxSharedPtr(T* ptr = NULL);
  33
  34     /**
  35         Copy constructor.
  36     */
  37     wxSharedPtr(const wxSharedPtr<T>& tocopy);
  38
  39     /**
  40         Destructor.
  41     */
  42     ~wxSharedPtr();
  43
  44     /**
  45         Returns pointer to its object or @NULL.
  46     */
  47     T* get() const;
  48
  49     /**
  50         Conversion to a boolean expression (in a variant which is not
  51         convertable to anything but a boolean expression).
  52
  53         If this class contains a valid pointer it will return @true, if it contains
  54         a @NULL pointer it will return @false.
  55     */
  56     operator unspecified_bool_type() const;
  57
  58     /**
  59         Returns a reference to the object.
  60
  61         If the internal pointer is @NULL this method will cause an assert in debug mode.
  62     */
  63     T operator*() const;
  64
  65     /**
  66         Returns pointer to its object or @NULL.
  67     */
  68     T* operator->() const;
  69
  70     /**
  71         Assignment operator.
  72
  73         Releases any previously held pointer and creates a reference to @a ptr.
  74     */
  75     wxSharedPtr<T>& operator=(T* ptr);
  76
  77     /**
  78         Assignment operator.
  79
  80         Releases any previously held pointer and creates a reference to the
  81         same object as @a topcopy.
  82     */
  83     wxSharedPtr<T>& operator=(const wxSharedPtr<T>& tocopy)
  84
  85     /**
  86         Reset pointer to @a ptr.
  87
  88         If the reference count of the previously owned pointer was 1 it will be deleted.
  89     */
  90     void reset(T* ptr = NULL);
  91
  92     /**
  93         Returns @true if this is the only pointer pointing to its object.
  94     */
  95     bool unique() const;
  96
  97     /**
  98         Returns the number of pointers pointing to its object.
  99     */
 100     long use_count() const;
 101 };
 102