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 wxPRE_NO_WARNING_SCOPE  for(int i=0;i<1;i++)
  44     #define wxPOST_NO_WARNING_SCOPE
  45 #else
  46     #define wxPRE_NO_WARNING_SCOPE  do
  47     #define wxPOST_NO_WARNING_SCOPE while ( 0 )
  48 #endif
  49
  50 #define wxCHECKED_DELETE(ptr)                                                 \
  51     wxPRE_NO_WARNING_SCOPE                                                    \
  52     {                                                                         \
  53         typedef char complete[sizeof(*ptr)];                                  \
  54         delete ptr;                                                           \
  55     } wxPOST_NO_WARNING_SCOPE
  56
  57 #define wxCHECKED_DELETE_ARRAY(ptr)                                           \
  58     wxPRE_NO_WARNING_SCOPE                                                    \
  59     {                                                                         \
  60         typedef char complete[sizeof(*ptr)];                                  \
  61         delete [] ptr;                                                        \
  62     } wxPOST_NO_WARNING_SCOPE
  63
  64 /* These scoped pointers are *not* assignable and cannot be used
  65    within a container.  Look for wxDECLARE_SHARED_PTR for this
  66    functionality.
  67
  68    In addition, the type being used *must* be complete at the time
  69    that wxDEFINE_SCOPED_* is called or a compiler error will result.
  70    This is because the class checks for the completeness of the type
  71    being used.
  72 */
  73
  74
  75 #define wxDECLARE_SCOPED_PTR(T, name) \
  76 class name                          \
  77 {                                   \
  78 private:                            \
  79     T * m_ptr;                      \
  80                                     \
  81     name(name const &);             \
  82     name & operator=(name const &); \
  83                                     \
  84 public:                             \
  85     wxEXPLICIT name(T * ptr = NULL) \
  86     : m_ptr(ptr) { }                \
  87                                     \
  88     ~name();                        \
  89                                     \
  90     void reset(T * ptr = NULL)      \
  91     {                               \
  92         if (m_ptr != ptr)           \
  93         {                           \
  94             delete m_ptr;           \
  95             m_ptr = ptr;            \
  96         }                           \
  97     }                               \
  98                                     \
  99     T *release()                    \
 100     {                               \
 101         T *ptr = m_ptr;             \
 102         m_ptr = NULL;               \
 103         return ptr;                 \
 104     }                               \
 105                                     \
 106     T & operator*() const           \
 107     {                               \
 108         wxASSERT(m_ptr != NULL);    \
 109         return *m_ptr;              \
 110     }                               \
 111                                     \
 112     T * operator->() const          \
 113     {                               \
 114         wxASSERT(m_ptr != NULL);    \
 115         return m_ptr;               \
 116     }                               \
 117                                     \
 118     T * get() const                 \
 119     {                               \
 120         return m_ptr;               \
 121     }                               \
 122                                     \
 123     void swap(name & ot)            \
 124     {                               \
 125         T * tmp = ot.m_ptr;         \
 126         ot.m_ptr = m_ptr;           \
 127         m_ptr = tmp;                \
 128     }                               \
 129 };
 130
 131 #define wxDEFINE_SCOPED_PTR(T, name)\
 132 name::~name()                       \
 133 {                                   \
 134     wxCHECKED_DELETE(m_ptr);        \
 135 }
 136
 137 // this macro can be used for the most common case when you want to declare and
 138 // define the scoped pointer at the same time and want to use the standard
 139 // naming convention: auto pointer to Foo is called FooPtr
 140 #define wxDEFINE_SCOPED_PTR_TYPE(T)                                           \
 141     wxDECLARE_SCOPED_PTR(T, T ## Ptr);                                        \
 142     wxDEFINE_SCOPED_PTR(T, T ## Ptr)
 143
 144 // the same but for arrays instead of simple pointers
 145 #define wxDECLARE_SCOPED_ARRAY(T, name)\
 146 class name                          \
 147 {                                   \
 148 private:                            \
 149     T * m_ptr;                      \
 150     name(name const &);             \
 151     name & operator=(name const &); \
 152                                     \
 153 public:                             \
 154     wxEXPLICIT name(T * p = NULL) : m_ptr(p) \
 155     {}                              \
 156                                     \
 157     ~name();                        \
 158     void reset(T * p = NULL);       \
 159                                     \
 160     T & operator[](long int i) const\
 161     {                               \
 162         wxASSERT(m_ptr != NULL);    \
 163         wxASSERT(i >= 0);           \
 164         return m_ptr[i];            \
 165     }                               \
 166                                     \
 167     T * get() const                 \
 168     {                               \
 169         return m_ptr;               \
 170     }                               \
 171                                     \
 172     void swap(name & ot)            \
 173     {                               \
 174         T * tmp = ot.m_ptr;         \
 175         ot.m_ptr = m_ptr;           \
 176         m_ptr = tmp;                \
 177     }                               \
 178 };
 179
 180 #define wxDEFINE_SCOPED_ARRAY(T, name)  \
 181 name::~name()                           \
 182 {                                       \
 183     wxCHECKED_DELETE_ARRAY(m_ptr);      \
 184 }                                       \
 185 void name::reset(T * p){                \
 186     if (m_ptr != p)                     \
 187     {                                   \
 188        wxCHECKED_DELETE_ARRAY(m_ptr);   \
 189        m_ptr = p;                       \
 190     }                                   \
 191 }
 192
 193 // ----------------------------------------------------------------------------
 194 // "Tied" scoped pointer: same as normal one but also sets the value of
 195 //                        some other variable to the pointer value
 196 // ----------------------------------------------------------------------------
 197
 198 #define wxDEFINE_TIED_SCOPED_PTR_TYPE(T)                                      \
 199     wxDEFINE_SCOPED_PTR_TYPE(T);                                              \
 200     class T ## TiedPtr : public T ## Ptr                                      \
 201     {                                                                         \
 202     public:                                                                   \
 203         T ## TiedPtr(T **pp, T *p)                                            \
 204             : T ## Ptr(p), m_pp(pp)                                           \
 205         {                                                                     \
 206             m_pOld = *pp;                                                     \
 207             *pp = p;                                                          \
 208         }                                                                     \
 209                                                                               \
 210         ~ T ## TiedPtr()                                                      \
 211         {                                                                     \
 212             *m_pp = m_pOld;                                                   \
 213         }                                                                     \
 214                                                                               \
 215     private:                                                                  \
 216         T **m_pp;                                                             \
 217         T *m_pOld;                                                            \
 218     }
 219
 220 #endif // __WX_SCOPED_POINTER__
 221