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56 lines
1.7 KiB
HTML
56 lines
1.7 KiB
HTML
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<html>
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<head>
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<title>BOOST_PP_TUPLE_ELEM</title>
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<link rel="stylesheet" type="text/css" href="../styles.css">
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<script language="javascript" type="text/javascript" src="../scripts.js"></script>
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</head>
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<body onload="init('sample');">
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<div style="margin-left: 0px;">
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The <b>BOOST_PP_TUPLE_ELEM</b> macro extracts an element from a <i>tuple</i>.
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</div>
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<h4>Usage</h4>
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<div class="code">
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<b>BOOST_PP_TUPLE_ELEM</b>(<i>size</i>, <i>i</i>, <i>tuple</i>)
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</div>
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<h4>Arguments</h4>
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<dl>
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<dt>size</dt>
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<dd>
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The size of the <i>tuple</i>.
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Valid <i>tuple</i> sizes range from <i>0</i> to <b>BOOST_PP_LIMIT_TUPLE</b>.
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</dd>
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<dt>i</dt>
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<dd>
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The zero-based index into the <i>tuple</i> of the element to be extracted.
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Valid values range from <i>0</i> to <i>size</i> - <i>1</i>.
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</dd>
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<dt>tuple</dt>
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<dd>
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The <i>tuple</i> from which an element is to be extracted.
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</dd>
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</dl>
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<h4>Remarks</h4>
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<div>
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The <i>size</i> argument must be the actual size of the <i>tuple</i>,
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and <i>i</i> must be less than the size of the <i>tuple</i>.
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</div>
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<h4>See Also</h4>
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<ul>
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<li><a href="limit_tuple.html">BOOST_PP_LIMIT_TUPLE</a></li>
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</ul>
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<h4>Requirements</h4>
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<div>
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<b>Header:</b> <a href="../headers/tuple/elem.hpp.html"><boost/preprocessor/tuple/elem.hpp></a>
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</div>
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<h4><a class="local" onclick="toggle('sample');" onmouseover="change(this);" onmouseout="revert(this);">Sample Code</a></h4>
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<div id="sample"><pre>
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#include <boost/preprocessor/tuple/elem.hpp>
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#define TUPLE (a, b, c, d)
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BOOST_PP_TUPLE_ELEM(4, 0, TUPLE) // expands to a
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BOOST_PP_TUPLE_ELEM(4, 3, TUPLE) // expands to d
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<pre></div>
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</body>
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</html>
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