preprocessor/doc/ref/list_to_tuple.html

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<title>BOOST_PP_LIST_TO_TUPLE</title>
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<div style="margin-left: 0px;"> The <b>BOOST_PP_LIST_TO_TUPLE</b> macro
converts a <i>list</i> to a <i>tuple</i>. </div>
<h4>Usage</h4>
<div class="code"> <b>BOOST_PP_LIST_TO_TUPLE</b>(<i>list</i>) </div>
<h4>Arguments</h4>
<dl>
<dt>list</dt>
<dd> The <i>list</i> to be converted. </dd>
</dl>
<h4>Remarks</h4>
<div> If <i>list</i> is, for example, (<i>a</i>, (<i>b</i>, (<i>c</i>, <b>BOOST_PP_NIL</b>))),
this macro will produce:
<div> (<i>a</i>, <i>b</i>, <i>c</i>) </div>
</div>
<div> Previously, this macro could not be used inside <b>BOOST_PP_FOR</b>.&nbsp;
There is no longer any such restriction.&nbsp; It is more efficient,
however, to use <b>BOOST_PP_LIST_TO_TUPLE_R</b> in such a situation.<br>
<br>
If the <i>list</i> to be converted is empty, as represented by 'BOOST_PP_NIL',
the resulting <i>tuple</i> is undefined since a <i>tuple</i> cannot be
empty.</div>
<h4>See Also</h4>
<ul>
<li><a href="list_to_tuple_r.html">BOOST_PP_LIST_TO_TUPLE_R</a></li>
</ul>
<h4>Requirements</h4>
<div> <b>Header:</b> &nbsp;<a href="../headers/list/to_tuple.html">&lt;boost/preprocessor/list/to_tuple.hpp&gt;</a>
</div>
<h4>Sample Code</h4>
<div>
<pre>#include &lt;<a href="../headers/list/to_tuple.html">boost/preprocessor/list/to_tuple.hpp</a>&gt;
#define LIST (w, (x, (y, (z, <a href="nil.html">BOOST_PP_NIL</a>))))
<a href="list_to_tuple.html">BOOST_PP_LIST_TO_TUPLE</a>(LIST) // expands to (w, x, y, z)
</pre></div>
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<div style="margin-left: 0px;"> <i>© Copyright <a href="http://www.housemarque.com"
target="_top">Housemarque Oy</a> 2002</i> <br>
<i>© Copyright Paul Mensonides 2002</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>
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