interface/wx/sharedptr.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        sharedptr.h
   3 // Purpose:     interface of wxSharedPtr<T>
   4 // Author:      wxWidgets team
   5 // Licence:     wxWindows licence
   6 /////////////////////////////////////////////////////////////////////////////
   7
   8 /**
   9     A smart pointer with non-intrusive reference counting.
  10
  11     It is modelled after @c boost::shared_ptr<> and can be used with STL
  12     containers and wxVector<T> unlike @c std::auto_ptr<> and wxScopedPtr<T>.
  13
  14     @library{wxbase}
  15     @category{smartpointers}
  16
  17     @see wxScopedPtr<T>, wxWeakRef<T>, wxObjectDataPtr<T>
  18 */
  19 template<typename T>
  20 class wxSharedPtr<T>
  21 {
  22 public:
  23     /**
  24         Constructor.
  25
  26         Creates shared pointer from the raw pointer @a ptr and takes ownership
  27         of it.
  28     */
  29     wxEXPLICIT wxSharedPtr(T* ptr = NULL);
  30
  31     /**
  32         Constructor.
  33
  34         Creates shared pointer from the raw pointer @a ptr and deleter @a d
  35         and takes ownership of it.
  36
  37         @param ptr  The raw pointer.
  38         @param d    Deleter - a functor that is called instead of delete to
  39                     free the @a ptr raw pointer when its reference count drops to
  40                     zero.
  41
  42         @since 3.0
  43     */
  44     template<typename Deleter>
  45     wxEXPLICIT wxSharedPtr(T* ptr, Deleter d);
  46
  47     /**
  48         Copy constructor.
  49     */
  50     wxSharedPtr(const wxSharedPtr<T>& tocopy);
  51
  52     /**
  53         Destructor.
  54     */
  55     ~wxSharedPtr();
  56
  57     /**
  58         Returns pointer to its object or @NULL.
  59     */
  60     T* get() const;
  61
  62     /**
  63         Conversion to a boolean expression (in a variant which is not
  64         convertible to anything but a boolean expression).
  65
  66         If this class contains a valid pointer it will return @true, if it contains
  67         a @NULL pointer it will return @false.
  68     */
  69     operator unspecified_bool_type() const;
  70
  71     /**
  72         Returns a reference to the object.
  73
  74         If the internal pointer is @NULL this method will cause an assert in debug mode.
  75     */
  76     T operator*() const;
  77
  78     /**
  79         Smart pointer member access. Returns pointer to its object.
  80
  81         If the internal pointer is @NULL this method will cause an assert in debug mode.
  82     */
  83     T* operator->() const;
  84
  85     /**
  86         Assignment operator.
  87
  88         Releases any previously held pointer and creates a reference to @a ptr.
  89     */
  90     wxSharedPtr<T>& operator=(T* ptr);
  91
  92     /**
  93         Assignment operator.
  94
  95         Releases any previously held pointer and creates a reference to the
  96         same object as @a topcopy.
  97     */
  98     wxSharedPtr<T>& operator=(const wxSharedPtr<T>& tocopy);
  99
 100     /**
 101         Reset pointer to @a ptr.
 102
 103         If the reference count of the previously owned pointer was 1 it will be deleted.
 104     */
 105     void reset(T* ptr = NULL);
 106
 107     /**
 108         Reset pointer to @a ptr.
 109
 110         If the reference count of the previously owned pointer was 1 it will be deleted.
 111
 112         @param ptr  The new raw pointer.
 113         @param d    Deleter - a functor that is called instead of delete to
 114                     free the @a ptr raw pointer when its reference count drops to
 115                     zero.
 116
 117         @since 3.0
 118     */
 119     template<typename Deleter>
 120     void reset(T* ptr, Deleter d);
 121
 122     /**
 123         Returns @true if this is the only pointer pointing to its object.
 124     */
 125     bool unique() const;
 126
 127     /**
 128         Returns the number of pointers pointing to its object.
 129     */
 130     long use_count() const;
 131 };
 132