devn00b
/
EQ2EMu


			
				
					
						
						
							12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758
							<html>
<head>
	<title>BOOST_PP_IDENTITY_N</title>
	<link rel="stylesheet" type="text/css" href="../styles.css">
</head>
<body>
	<div style="margin-left:  0px;">
	    The <b>BOOST_PP_IDENTITY_N</b> macro expands to its first argument when invoked.
	</div>
	<h4>Usage</h4>
		<div class="code">
			<b>BOOST_PP_IDENTITY_N</b>(<i>item,n</i>)(n-arguments)
		</div>
	<h4>Arguments</h4>
		<dl>
			<dt>item</dt>
			<dd>
				The result of the expansion.
			</dd>
			<dt>n</dt>
			<dd>
				The number of arguments when invoked.
			</dd>
		</dl>
	<h4>Remarks</h4>
		<div>
			This macro is designed to be used with <b>BOOST_PP_IF</b> and <b>BOOST_PP_IIF</b> when only one of the clauses needs to be invoked.
		</div>
	<h4>See Also</h4>
		<ul>
			<li><a href="if.html">BOOST_PP_IF</a></li>
			<li><a href="iif.html">BOOST_PP_IIF</a></li>
		</ul>
	<h4>Requirements</h4>
		<div>
			<b>Header:</b> &nbsp;<a href="../headers/facilities/identity.html">&lt;boost/preprocessor/facilities/identity.hpp&gt;</a>
		</div>
	<h4>Sample Code</h4>
<div><pre>
#include &lt;<a href="../headers/control/if.html">boost/preprocessor/control/if.hpp</a>&gt;
#include &lt;<a href="../headers/facilities/identity.html">boost/preprocessor/facilities/identity.hpp</a>&gt;

#define MACRO_CAT(y,z) y ## z
#define MACRO(n) <a href="if.html">BOOST_PP_IF</a>(n, <a href="identity_n.html">BOOST_PP_IDENTITY_N</a>(x,2), MACRO_CAT)(a,b)

MACRO(0) // expands to ab
MACRO(1) // expands to x
</pre></div>
	<hr size="1">
    <div style="margin-left: 0px"><i>&copy; Copyright Edward Diener 2015</i></div>
	<div style="margin-left: 0px;">
		<p><small>Distributed under the Boost Software License, Version 1.0. (See
		accompanying file <a href="../../../../LICENSE_1_0.txt">LICENSE_1_0.txt</a> or
		copy at <a href=
		"http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt</a>)</small></p>
	</div>
</body>
</html>