<html lang="en"> <head> <title>compatibility_alias - Using the GNU Compiler Collection (GCC)</title> <meta http-equiv="Content-Type" content="text/html"> <meta name="description" content="Using the GNU Compiler Collection (GCC)"> <meta name="generator" content="makeinfo 4.13"> <link title="Top" rel="start" href="index.html#Top"> <link rel="up" href="Objective_002dC.html#Objective_002dC" title="Objective-C"> <link rel="prev" href="Constant-string-objects.html#Constant-string-objects" title="Constant string objects"> <link rel="next" href="Exceptions.html#Exceptions" title="Exceptions"> <link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> <!-- Copyright (C) 1988-2015 Free Software Foundation, Inc. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with the Invariant Sections being ``Funding Free Software'', the Front-Cover Texts being (a) (see below), and with the Back-Cover Texts being (b) (see below). A copy of the license is included in the section entitled ``GNU Free Documentation License''. (a) The FSF's Front-Cover Text is: A GNU Manual (b) The FSF's Back-Cover Text is: You have freedom to copy and modify this GNU Manual, like GNU software. Copies published by the Free Software Foundation raise funds for GNU development.--> <meta http-equiv="Content-Style-Type" content="text/css"> <style type="text/css"><!-- pre.display { font-family:inherit } pre.format { font-family:inherit } pre.smalldisplay { font-family:inherit; font-size:smaller } pre.smallformat { font-family:inherit; font-size:smaller } pre.smallexample { font-size:smaller } pre.smalllisp { font-size:smaller } span.sc { font-variant:small-caps } span.roman { font-family:serif; font-weight:normal; } span.sansserif { font-family:sans-serif; font-weight:normal; } --></style> </head> <body> <div class="node"> <a name="compatibility_alias"></a> <a name="compatibility_005falias"></a> <p> Next: <a rel="next" accesskey="n" href="Exceptions.html#Exceptions">Exceptions</a>, Previous: <a rel="previous" accesskey="p" href="Constant-string-objects.html#Constant-string-objects">Constant string objects</a>, Up: <a rel="up" accesskey="u" href="Objective_002dC.html#Objective_002dC">Objective-C</a> <hr> </div> <h3 class="section">8.6 <code>compatibility_alias</code></h3> <p>The keyword <code>@compatibility_alias</code> allows you to define a class name as equivalent to another class name. For example: <pre class="smallexample"> @compatibility_alias WOApplication GSWApplication; </pre> <p>tells the compiler that each time it encounters <code>WOApplication</code> as a class name, it should replace it with <code>GSWApplication</code> (that is, <code>WOApplication</code> is just an alias for <code>GSWApplication</code>). <p>There are some constraints on how this can be used— <ul> <li><code>WOApplication</code> (the alias) must not be an existing class; <li><code>GSWApplication</code> (the real class) must be an existing class. </ul> <!-- ========================================================================= --> </body></html>