include/wx/ptr_scpd.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/ptr_scpd.h
   3 // Purpose:     scoped smart pointer class
   4 // Author:      Jesse Lovelace <jllovela@eos.ncsu.edu>
   5 // Modified by:
   6 // Created:     06/01/02
   7 // RCS-ID:      $Id$
   8 // Copyright:   (c) Jesse Lovelace and original Boost authors (see below)
   9 // Licence:     wxWindows licence
  10 /////////////////////////////////////////////////////////////////////////////
  11
  12 //  This class closely follows the implementation of the boost
  13 //  library scoped_ptr and is an adaption for c++ macro's in
  14 //  the wxWidgets project. The original authors of the boost
  15 //  scoped_ptr are given below with their respective copyrights.
  16
  17 //  (C) Copyright Greg Colvin and Beman Dawes 1998, 1999.
  18 //  Copyright (c) 2001, 2002 Peter Dimov
  19 //
  20 //  Permission to copy, use, modify, sell and distribute this software
  21 //  is granted provided this copyright notice appears in all copies.
  22 //  This software is provided "as is" without express or implied
  23 //  warranty, and with no claim as to its suitability for any purpose.
  24 //
  25 //  See http://www.boost.org/libs/smart_ptr/scoped_ptr.htm for documentation.
  26 //
  27
  28 #ifndef __WX_SCOPED_POINTER__
  29 #define __WX_SCOPED_POINTER__
  30
  31 #include "wx/defs.h"
  32
  33 /*
  34    checked deleters are used to make sure that the type being deleted is really
  35    a complete type.: otherwise sizeof() would result in a compile-time error
  36
  37    do { ... } while ( 0 ) construct is used to have an anonymous scope
  38    (otherwise we could have name clashes between different "complete"s) but
  39    still force a semicolon after the macro
  40 */
  41
  42 #ifdef __WATCOMC__
  43     #define wxFOR_ONCE(name)              for(int name=0; name<1; name++)
  44     #define wxPRE_NO_WARNING_SCOPE(name)  wxFOR_ONCE(wxMAKE_UNIQUE_NAME(name))
  45     #define wxPOST_NO_WARNING_SCOPE(name)
  46 #else
  47     #define wxPRE_NO_WARNING_SCOPE(name)  do
  48     #define wxPOST_NO_WARNING_SCOPE(name) while ( wxFalse )
  49 #endif
  50
  51 #define wxCHECKED_DELETE(ptr)                                                 \
  52     wxPRE_NO_WARNING_SCOPE(scope_var1)                                        \
  53     {                                                                         \
  54         typedef char complete[sizeof(*ptr)];                                  \
  55         delete ptr;                                                           \
  56     } wxPOST_NO_WARNING_SCOPE(scope_var1)
  57
  58 #define wxCHECKED_DELETE_ARRAY(ptr)                                           \
  59     wxPRE_NO_WARNING_SCOPE(scope_var2)                                        \
  60     {                                                                         \
  61         typedef char complete[sizeof(*ptr)];                                  \
  62         delete [] ptr;                                                        \
  63     } wxPOST_NO_WARNING_SCOPE(scope_var2)
  64
  65 /* These scoped pointers are *not* assignable and cannot be used
  66    within a container.  Look for wxDECLARE_SHARED_PTR for this
  67    functionality.
  68
  69    In addition, the type being used *must* be complete at the time
  70    that wxDEFINE_SCOPED_* is called or a compiler error will result.
  71    This is because the class checks for the completeness of the type
  72    being used.
  73 */
  74
  75
  76 #define wxDECLARE_SCOPED_PTR(T, name) \
  77 class name                          \
  78 {                                   \
  79 private:                            \
  80     T * m_ptr;                      \
  81                                     \
  82     name(name const &);             \
  83     name & operator=(name const &); \
  84                                     \
  85 public:                             \
  86     wxEXPLICIT name(T * ptr = NULL) \
  87     : m_ptr(ptr) { }                \
  88                                     \
  89     ~name();                        \
  90                                     \
  91     void reset(T * ptr = NULL)      \
  92     {                               \
  93         if (m_ptr != ptr)           \
  94         {                           \
  95             delete m_ptr;           \
  96             m_ptr = ptr;            \
  97         }                           \
  98     }                               \
  99                                     \
 100     T *release()                    \
 101     {                               \
 102         T *ptr = m_ptr;             \
 103         m_ptr = NULL;               \
 104         return ptr;                 \
 105     }                               \
 106                                     \
 107     T & operator*() const           \
 108     {                               \
 109         wxASSERT(m_ptr != NULL);    \
 110         return *m_ptr;              \
 111     }                               \
 112                                     \
 113     T * operator->() const          \
 114     {                               \
 115         wxASSERT(m_ptr != NULL);    \
 116         return m_ptr;               \
 117     }                               \
 118                                     \
 119     T * get() const                 \
 120     {                               \
 121         return m_ptr;               \
 122     }                               \
 123                                     \
 124     void swap(name & ot)            \
 125     {                               \
 126         T * tmp = ot.m_ptr;         \
 127         ot.m_ptr = m_ptr;           \
 128         m_ptr = tmp;                \
 129     }                               \
 130 };
 131
 132 #define wxDEFINE_SCOPED_PTR(T, name)\
 133 name::~name()                       \
 134 {                                   \
 135     wxCHECKED_DELETE(m_ptr);        \
 136 }
 137
 138 // this macro can be used for the most common case when you want to declare and
 139 // define the scoped pointer at the same time and want to use the standard
 140 // naming convention: auto pointer to Foo is called FooPtr
 141 #define wxDEFINE_SCOPED_PTR_TYPE(T)    \
 142     wxDECLARE_SCOPED_PTR(T, T ## Ptr)  \
 143     wxDEFINE_SCOPED_PTR(T, T ## Ptr)
 144
 145 // the same but for arrays instead of simple pointers
 146 #define wxDECLARE_SCOPED_ARRAY(T, name)\
 147 class name                          \
 148 {                                   \
 149 private:                            \
 150     T * m_ptr;                      \
 151     name(name const &);             \
 152     name & operator=(name const &); \
 153                                     \
 154 public:                             \
 155     wxEXPLICIT name(T * p = NULL) : m_ptr(p) \
 156     {}                              \
 157                                     \
 158     ~name();                        \
 159     void reset(T * p = NULL);       \
 160                                     \
 161     T & operator[](long int i) const\
 162     {                               \
 163         wxASSERT(m_ptr != NULL);    \
 164         wxASSERT(i >= 0);           \
 165         return m_ptr[i];            \
 166     }                               \
 167                                     \
 168     T * get() const                 \
 169     {                               \
 170         return m_ptr;               \
 171     }                               \
 172                                     \
 173     void swap(name & ot)            \
 174     {                               \
 175         T * tmp = ot.m_ptr;         \
 176         ot.m_ptr = m_ptr;           \
 177         m_ptr = tmp;                \
 178     }                               \
 179 };
 180
 181 #define wxDEFINE_SCOPED_ARRAY(T, name)  \
 182 name::~name()                           \
 183 {                                       \
 184     wxCHECKED_DELETE_ARRAY(m_ptr);      \
 185 }                                       \
 186 void name::reset(T * p){                \
 187     if (m_ptr != p)                     \
 188     {                                   \
 189        wxCHECKED_DELETE_ARRAY(m_ptr);   \
 190        m_ptr = p;                       \
 191     }                                   \
 192 }
 193
 194 // ----------------------------------------------------------------------------
 195 // "Tied" scoped pointer: same as normal one but also sets the value of
 196 //                        some other variable to the pointer value
 197 // ----------------------------------------------------------------------------
 198
 199 #define wxDEFINE_TIED_SCOPED_PTR_TYPE(T)                                      \
 200     wxDEFINE_SCOPED_PTR_TYPE(T)                                               \
 201     class T ## TiedPtr : public T ## Ptr                                      \
 202     {                                                                         \
 203     public:                                                                   \
 204         T ## TiedPtr(T **pp, T *p)                                            \
 205             : T ## Ptr(p), m_pp(pp)                                           \
 206         {                                                                     \
 207             m_pOld = *pp;                                                     \
 208             *pp = p;                                                          \
 209         }                                                                     \
 210                                                                               \
 211         ~ T ## TiedPtr()                                                      \
 212         {                                                                     \
 213             *m_pp = m_pOld;                                                   \
 214         }                                                                     \
 215                                                                               \
 216     private:                                                                  \
 217         T **m_pp;                                                             \
 218         T *m_pOld;                                                            \
 219     };
 220
 221 #endif // __WX_SCOPED_POINTER__
 222