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2002-10-13 05:47:23 +00:00
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<title>BOOST_PP_SET_TRANSFORM</title>
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<div style="margin-left: 0px;">
The <b>BOOST_PP_SET_TRANSFORM</b> macro transforms each element in a <i>set</i> according to a supplied transformation.
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<h4>Usage</h4>
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<b>BOOST_PP_SET_TRANSFORM</b>(<i>op</i>, <i>data</i>, <i>set</i>)
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<h4>Arguments</h4>
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<dt>op</dt>
<dd>
A ternary predicate of the form <i>op</i>(<i>s</i>, <i>data</i>, <i>elem</i>).&nbsp;
This transformation is expanded by <b>BOOST_PP_SET_TRANSFORM</b> for each element in <i>set</i> with the next available <b>BOOST_PP_SET_FOLD_LEFT</b> fold step,
the auxiliary <i>data</i>, and the current element in <i>set</i>.&nbsp;
</dd>
<dt>data</dt>
<dd>
Auxiliary data passed to <i>pred</i>.
</dd>
<dt>set</dt>
<dd>
The <i>set</i> to be transformed.
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</dl>
<h4>Remarks</h4>
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This macro expands <i>op</i> for each element in <i>set</i>.&nbsp;
It builds a new <i>set</i> out of the results of each call.&nbsp;
If, for example, <i>set</i> is (<i>a</i>)(<i>b</i>)(<i>c</i>),
this macro expands to...
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(<i>op</i>(<i>d</i>, <i>data</i>, <i>a</i>))(<i>op</i>(<i>d</i>, <i>data</i>, <i>b</i>))(<i>op</i>(<i>d</i>, <i>data</i>, <i>c</i>))
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For maximum efficiency, use <b>BOOST_PP_SET_TRANSFORM_S</b>.
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<h4>See Also</h4>
<ul>
<li><a href="set_transform_s.html">BOOST_PP_SET_TRANSFORM_S</a></li>
</ul>
<h4>Requirements</h4>
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<b>Header:</b> &nbsp;<a href="../headers/set/transform.hpp.html">&lt;boost/preprocessor/set/transform.hpp&gt;</a>
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<h4>Sample Code</h4>
<div><pre>
#include &lt;<a href="../headers/arithmetic/dec.hpp.html">boost/preprocessor/arithmetic/dec.hpp</a>&gt;
#include &lt;<a href="../headers/set/transform.hpp.html">boost/preprocessor/set/transform.hpp</a>&gt;
#define SET (1)(3)(2)(5)
#define OP(s, data, elem) <a href="dec.html">BOOST_PP_DEC</a>(elem)
<a href="set_transform.html">BOOST_PP_SET_TRANSFORM</a>(OP, 3, SET)
// expands to (0)(2)(1)(4)
</pre></div>
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