[thirdparty/gcc.git] / gcc / doc / gcc / gnu-objective-c-features / compatibilityalias.rst

..
  Copyright 1988-2022 Free Software Foundation, Inc.
  This is part of the GCC manual.
  For copying conditions, see the copyright.rst file.

.. _compatibility_alias:

compatibility_alias
*******************

The keyword ``@compatibility_alias`` allows you to define a class name
as equivalent to another class name.  For example:

.. code-block:: objective-c

  @compatibility_alias WOApplication GSWApplication;

tells the compiler that each time it encounters ``WOApplication`` as
a class name, it should replace it with ``GSWApplication`` (that is,
``WOApplication`` is just an alias for ``GSWApplication``).

There are some constraints on how this can be used---

* ``WOApplication`` (the alias) must not be an existing class;

* ``GSWApplication`` (the real class) must be an existing class.
Commit	Line	Data
c63539ff ML	1	..
	2	Copyright 1988-2022 Free Software Foundation, Inc.
	3	This is part of the GCC manual.
	4	For copying conditions, see the copyright.rst file.
	5
	6	.. _compatibility_alias:
	7
	8	compatibility_alias
	9	*******************
	10
	11	The keyword ``@compatibility_alias`` allows you to define a class name
	12	as equivalent to another class name. For example:
	13
	14	.. code-block:: objective-c
	15
	16	@compatibility_alias WOApplication GSWApplication;
	17
	18	tells the compiler that each time it encounters ``WOApplication`` as
	19	a class name, it should replace it with ``GSWApplication`` (that is,
	20	``WOApplication`` is just an alias for ``GSWApplication``).
	21
	22	There are some constraints on how this can be used---
	23
	24	* ``WOApplication`` (the alias) must not be an existing class;
	25
3ed1b4ce	26	* ``GSWApplication`` (the real class) must be an existing class.