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         Smart pointer member access. Returns pointer to its object.
  65
  66         If the internal pointer is @NULL this method will cause an assert in debug mode.
  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