docs/latex/wx/scpdptr.tex

   1 \section{\class{wxScopedPtr}}\label{wxscopedptr}
   2
   3 This is a simple scoped smart pointer implementation that is similar to
   4 the \urlref{Boost}{http://www.boost.org} smart pointers but rewritten to
   5 use macros instead.
   6
   7 \wxheading{Example}
   8
   9 Below is an example of using a wxWindows scoped smart pointer and
  10 pointer array.
  11
  12 \begin{verbatim}
  13   class MyClass { /* ... */ };
  14
  15   // declare a smart pointer to a MyClass called wxMyClassPtr
  16   wxDECLARE_SCOPED_PTR(MyClass, wxMyClassPtr)
  17   // declare a smart pointer to an array of chars
  18   wxDECLARE_SCOPED_ARRAY(char, wxCharArray)
  19
  20   ...
  21
  22   // define the first pointer class, must be complete
  23   wxDEFINE_SCOPED_PTR(MyClass, wxMyClassPtr)
  24   // define the second pointer class
  25   wxDEFINE_SCOPED_ARRAY(char, wxCharArray)
  26
  27   // create an object with a new pointer to MyClass
  28   wxMyClassPtr theObj(new MyClass());
  29   // reset the pointer (deletes the previous one)
  30   theObj.reset(new MyClass());
  31
  32   // access the pointer
  33   theObj->MyFunc();
  34
  35   // create an object with a new array of chars
  36   wxCharArray theCharObj(new char[100]);
  37
  38   // access the array
  39   theCharObj[0] = "!";
  40 \end{verbatim}
  41
  42 \wxheading{Declaring new smart pointer types}
  43
  44 \begin{verbatim}
  45     wxDECLAR_SCOPED_PTR( TYPE,     // type of the values
  46                                 CLASSNAME ); // name of the class
  47 \end{verbatim}
  48
  49 A smart pointer holds a pointer to an object (which must be complete
  50 when wxDEFINE\_SCOPED\_PTR() is called). The memory used by the object is
  51 deleted when the smart pointer goes out of scope. The first argument
  52 of the macro is the pointer type, the second is the name of the new
  53 smart pointer class being created.  Below we will use wxScopedPtr to
  54 represent the scoped pointer class, but the user may create the class with any
  55 legal name.
  56
  57 \wxheading{Include files}
  58
  59 <wx/ptr\_scpd.h>
  60
  61 \wxheading{See also}
  62
  63 \helpref{wxScopedArray}{wxscopedarray}\rtfsp
  64
  65 \latexignore{\rtfignore{\wxheading{Members}}}
  66
  67 \membersection{wxScopedPtr::wxScopedPtr}
  68
  69 \func{}{wxScopedPtr}{\param{type}{ * T = NULL}}
  70
  71 Creates the smart pointer with the given pointer or none if NULL.  On
  72 compilers that support it, this uses the explicit keyword.
  73
  74 \membersection{wxScopedPtr::reset}
  75
  76 \func{\void}{reset}{\param{T}{ p * = NULL}}
  77
  78 Deletes the currently held pointer and sets it to 'p' or to NULL if no
  79 arguments are specified. This function does check to make sure that the
  80 pointer you are assigning is not the same pointer that is already stored.
  81
  82 \membersection{wxScopedPtr::operator *}
  83
  84 \func{const T\&}{operator *}{\void}
  85
  86 This operator works like the standard C++ pointer operator to return the object
  87 being pointed to by the pointer.  If the pointer is NULL or invalid this will
  88 crash.
  89
  90 \membersection{wxScopedPtr::operator -\>}
  91
  92 \func{const T*}{operator -\>}{\void}
  93
  94 This operator works like the standard C++ pointer operator to return the pointer
  95 in the smart pointer or NULL if it is empty.
  96
  97 \membersection{wxScopedPtr::get}
  98
  99 \func{const T*}{get}{\void}
 100
 101 This operator gets the pointer stored in the smart pointer or returns NULL if
 102 there is none.
 103
 104 \membersection{wxScopedPtr::swap}
 105
 106 \func{\void}{swap}{\param{wxScopedPtr}{ \& ot}}
 107
 108 Swap the pointer inside the smart pointer with 'ot'. The pointer being swapped
 109 must be of the same type (hence the same class name).
 110