baseoffset.hh

C++ Reflection & Service Library

#ifndef RFL_BASEOFFSET_HH
#define RFL_BASEOFFSET_HH
/* C++ Reflection & Serice Library
 * Copyright (C) 2003  Marcus Perlick
 * mailto: [e-mail]
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 * 
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
 * USA
 *
 * This file is part of the "C++ Reflection & Serice Library" */

/** If class D is derived from class A and B, type
 *  <code>OffsetOf<B>::inClass<D></code> to compute the offset of B within
 *  D. */
template<typename B>
struct OffsetOf {
  template<typename D>
  static unsigned int inClass( void ) 
  {
    int tmp = (int)&static_cast<B&>(*(D*)4);
    return tmp - 4;
  }
};

#endif // RFL_BASEOFFSET_HH