1  /* Interface for the Object class for Objective-C.
       2     Copyright (C) 1993-2023 Free Software Foundation, Inc.
       3  
       4  This file is part of GCC.
       5  
       6  GCC is free software; you can redistribute it and/or modify it
       7  under the terms of the GNU General Public License as published by the
       8  Free Software Foundation; either version 3, or (at your option) any
       9  later version.
      10  
      11  GCC is distributed in the hope that it will be useful, but WITHOUT
      12  ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
      13  FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
      14  License for more details.
      15  
      16  Under Section 7 of GPL version 3, you are granted additional
      17  permissions described in the GCC Runtime Library Exception, version
      18  3.1, as published by the Free Software Foundation.
      19  
      20  You should have received a copy of the GNU General Public License and
      21  a copy of the GCC Runtime Library Exception along with this program;
      22  see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
      23  <http://www.gnu.org/licenses/>.  */
      24  
      25  
      26  #ifndef __object_INCLUDE_GNU
      27  #define __object_INCLUDE_GNU
      28  
      29  #include "objc.h"
      30  
      31  #ifdef __cplusplus
      32  extern "C" {
      33  #endif
      34  
      35  /* The Object class is a very minimal root class included with the
      36     runtime.  It is used as superclass for the two classes included
      37     with the runtime, Protocol and NXConstantString.
      38  
      39     Because Objective-C allows multiple root classes, you can define
      40     your own root class, different from Object.
      41  
      42     In particular, a Foundation library (such as GNUstep Base) is
      43     expected to provide its own root class (typically called NSObject),
      44     fully integrated with the library's own high-level features.  It is
      45     expected that you should always use and interact with NSObject, and
      46     mostly ignore Object.  */
      47  
      48  /* All classes are derived from Object.  As such, this is the overhead
      49     tacked onto those objects.  */
      50  @interface Object
      51  {
      52    Class isa; /* A pointer to the instance's class structure.  */
      53  }
      54  - (Class)class;
      55  - (BOOL)isEqual: (id)anObject;
      56  @end
      57  
      58  #ifdef __cplusplus
      59  }
      60  #endif
      61  
      62  #endif