include/wx/meta/convertible.h

   1 /////////////////////////////////////////////////////////////////////////////
   2 // Name:        wx/meta/convertible.h
   3 // Purpose:     Test if types are convertible
   4 // Author:      Arne Steinarson
   5 // Created:     2008-01-10
   6 // RCS-ID:      $Id$
   7 // Copyright:   (c) 2008 Arne Steinarson
   8 // Licence:     wxWindows licence
   9 /////////////////////////////////////////////////////////////////////////////
  10
  11 #ifndef _WX_META_CONVERTIBLE_H_
  12 #define _WX_META_CONVERTIBLE_H_
  13
  14 // Helper to decide if an object of type D is convertible to type B (the test
  15 // succeeds in particular when D derives from B)
  16 template <class D, class B>
  17 struct wxConvertibleTo
  18 {
  19     static char Match(B* pb);
  20     static int Match(...);
  21
  22     enum { value = sizeof(Match(static_cast<D*>(NULL))) == sizeof(char) };
  23 };
  24
  25 #endif // _WX_META_CONVERTIBLE_H_
  26