include/wx/typeinfo.h

   1 ///////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/typeinfo.h
   3 // Purpose:     wxTypeId implementation
   4 // Author:      Jaakko Salli
   5 // Created:     2009-11-19
   6 // RCS-ID:      $Id$
   7 // Copyright:   (c) wxWidgets Team
   8 // Licence:     wxWindows licence
   9 ///////////////////////////////////////////////////////////////////////////////
  10
  11 #ifndef _WX_TYPEINFO_H_
  12 #define _WX_TYPEINFO_H_
  13
  14 //
  15 // This file defines wxTypeId macro that should be used internally in
  16 // wxWidgets instead of typeid(), for compatibility with builds that do
  17 // not implement C++ RTTI. Also, type defining macros in this file are also
  18 // intended for internal use only at this time and may change in future
  19 // versions.
  20 //
  21
  22 #include "wx/defs.h"
  23
  24 #ifndef wxNO_RTTI
  25
  26 #include <typeinfo>
  27 #include <string.h>
  28
  29 #define _WX_DECLARE_TYPEINFO_CUSTOM(CLS, IDENTFUNC)
  30 #define WX_DECLARE_TYPEINFO_INLINE(CLS)
  31 #define WX_DECLARE_TYPEINFO(CLS)
  32 #define WX_DEFINE_TYPEINFO(CLS)
  33 #define WX_DECLARE_ABSTRACT_TYPEINFO(CLS)
  34
  35 //
  36 // For improved type-safety, let's make the check using class name
  37 // comparison. Most modern compilers already do this, but we cannot
  38 // rely on all supported compilers to work this well. However, in
  39 // cases where we'd know that typeid() would be flawless (as such),
  40 // wxTypeId could of course simply be defined as typeid.
  41 //
  42
  43 class wxTypeInfo
  44 {
  45 public:
  46     wxTypeInfo(const char* className)
  47     {
  48         m_className = className;
  49     }
  50
  51     bool operator==(const wxTypeInfo& other)
  52     {
  53         return strcmp(m_className, other.m_className) == 0;
  54     }
  55
  56     bool operator!=(const wxTypeInfo& other)
  57     {
  58         return strcmp(m_className, other.m_className) != 0;
  59     }
  60 private:
  61     const char* m_className;
  62 };
  63
  64 #define wxTypeId(OBJ) wxTypeInfo(typeid(OBJ).name())
  65
  66 #else // if !wxNO_RTTI
  67
  68 //
  69 // When C++ RTTI is not available, we will have to make the type comparison
  70 // using pointer to a dummy static member function. This will fail if
  71 // declared type is used across DLL boundaries, although using
  72 // WX_DECLARE_TYPEINFO() and WX_DEFINE_TYPEINFO() pair instead of
  73 // WX_DECLARE_TYPEINFO_INLINE() should fix this. However, that approach is
  74 // usually not possible when type info needs to be declared for a template
  75 // class.
  76 //
  77
  78 typedef void (*wxTypeIdentifier)();
  79
  80 // Use this macro to declare type info with specified static function
  81 // IDENTFUNC used as type identifier. Usually you should only use
  82 // WX_DECLARE_TYPEINFO() or WX_DECLARE_TYPEINFO_INLINE() however.
  83 #define _WX_DECLARE_TYPEINFO_CUSTOM(CLS, IDENTFUNC) \
  84 public: \
  85     virtual wxTypeIdentifier GetWxTypeId() const \
  86     { \
  87         return reinterpret_cast<wxTypeIdentifier> \
  88             (&IDENTFUNC); \
  89     }
  90
  91 // Use this macro to declare type info with externally specified
  92 // type identifier, defined with WX_DEFINE_TYPEINFO().
  93 #define WX_DECLARE_TYPEINFO(CLS) \
  94 private: \
  95     static CLS sm_wxClassInfo(); \
  96 _WX_DECLARE_TYPEINFO_CUSTOM(CLS, sm_wxClassInfo)
  97
  98 // Use this macro to implement type identifier function required by
  99 // WX_DECLARE_TYPEINFO().
 100 // NOTE: CLS is required to have default ctor. If it doesn't
 101 //       already, you should provide a private dummy one.
 102 #define WX_DEFINE_TYPEINFO(CLS) \
 103 CLS CLS::sm_wxClassInfo() { return CLS(); }
 104
 105 // Use this macro to declare type info fully inline in class.
 106 // NOTE: CLS is required to have default ctor. If it doesn't
 107 //       already, you should provide a private dummy one.
 108 #define WX_DECLARE_TYPEINFO_INLINE(CLS) \
 109 private: \
 110     static CLS sm_wxClassInfo() { return CLS(); } \
 111 _WX_DECLARE_TYPEINFO_CUSTOM(CLS, sm_wxClassInfo)
 112
 113 #define wxTypeId(OBJ) (OBJ).GetWxTypeId()
 114
 115 // Because abstract classes cannot be instantiated, we use
 116 // this macro to define pure virtual type interface for them.
 117 #define WX_DECLARE_ABSTRACT_TYPEINFO(CLS) \
 118 public: \
 119     virtual wxTypeIdentifier GetWxTypeId() const = 0;
 120
 121 #endif // wxNO_RTTI/!wxNO_RTTI
 122
 123 #endif // _WX_TYPEINFO_H_