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         Copy constructor.
  33     */
  34     wxSharedPtr(const wxSharedPtr<T>& tocopy);
  35
  36     /**
  37         Destructor.
  38     */
  39     ~wxSharedPtr();
  40
  41     /**
  42         Returns pointer to its object or @NULL.
  43     */
  44     T* get() const;
  45
  46     /**
  47         Conversion to a boolean expression (in a variant which is not
  48         convertible to anything but a boolean expression).
  49
  50         If this class contains a valid pointer it will return @true, if it contains
  51         a @NULL pointer it will return @false.
  52     */
  53     operator unspecified_bool_type() const;
  54
  55     /**
  56         Returns a reference to the object.
  57
  58         If the internal pointer is @NULL this method will cause an assert in debug mode.
  59     */
  60     T operator*() const;
  61
  62     /**
  63         Smart pointer member access. Returns pointer to its object.
  64
  65         If the internal pointer is @NULL this method will cause an assert in debug mode.
  66     */
  67     T* operator->() const;
  68
  69     /**
  70         Assignment operator.
  71
  72         Releases any previously held pointer and creates a reference to @a ptr.
  73     */
  74     wxSharedPtr<T>& operator=(T* ptr);
  75
  76     /**
  77         Assignment operator.
  78
  79         Releases any previously held pointer and creates a reference to the
  80         same object as @a topcopy.
  81     */
  82     wxSharedPtr<T>& operator=(const wxSharedPtr<T>& tocopy);
  83
  84     /**
  85         Reset pointer to @a ptr.
  86
  87         If the reference count of the previously owned pointer was 1 it will be deleted.
  88     */
  89     void reset(T* ptr = NULL);
  90
  91     /**
  92         Returns @true if this is the only pointer pointing to its object.
  93     */
  94     bool unique() const;
  95
  96     /**
  97         Returns the number of pointers pointing to its object.
  98     */
  99     long use_count() const;
 100 };
 101