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boost_preprocessor/doc/ref/set_for_each_i.html

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<title>BOOST_PP_SET_FOR_EACH_I</title>
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The <b>BOOST_PP_SET_FOR_EACH_I</b> macro repeats a macro for each element in a <i>set</i>.
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<h4>Usage</h4>
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<b>BOOST_PP_SET_FOR_EACH_I</b>(<i>macro</i>, <i>data</i>, <i>set</i>)
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<h4>Arguments</h4>
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<dt>macro</dt>
<dd>
A macro of the form <i>macro</i>(<i>r</i>, <i>data</i>, <i>i</i>, <i>elem</i>).&nbsp;
This macro is expanded by <b>BOOST_PP_SET_FOR_EACH_I</b> with each element in <i>set</i>.&nbsp;
It is expanded with the next available <b>BOOST_PP_FOR</b> repetition, the auxiliary <i>data</i>, the index of the current element, and the current element.
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<dt>data</dt>
<dd>
Auxiliary data passed to <i>macro</i>.
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<dt>set</dt>
<dd>
The <i>set</i> for which <i>macro</i> will be invoked on each element.
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<h4>Remarks</h4>
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This macro is a repetition construct.&nbsp;
If <i>set</i> is (<i>a</i>)(<i>b</i>)(<i>c</i>), it expands to the sequence:
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<i>macro</i>(<i>r</i>, <i>data</i>, <i>0</i>, <i>a</i>) <i>macro</i>(<i>r</i>, <i>data</i>, <i>1</i>, <i>b</i>) <i>macro</i>(<i>r</i>, <i>data</i>, <i>2</i>, <i>c</i>)
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For maximum efficiency, use <b>BOOST_PP_SET_FOR_EACH_I_R</a></li>
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<h4>See Also</h4>
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<li><a href="set_for_each_i_r.html">BOOST_PP_SET_FOR_EACH_I_R</a></li>
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<h4>Requirements</h4>
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<b>Header:</b> &nbsp;<a href="../headers/set/for_each_i.hpp.html">&lt;boost/preprocessor/set/for_each_i.hpp&gt;</a>
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<h4>Sample Code</h4>
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#include &lt;<a href="../headers/cat.hpp.html">boost/preprocessor/cat.hpp</a>&gt;
#include &lt;<a href="../headers/set/for_each_i.hpp.html">boost/preprocessor/set/for_each_i.hpp</a>&gt;
#define SET (a)(b)(c)(d)
#define MACRO(r, data, i, elem) <a href="cat.html">BOOST_PP_CAT</a>(elem, <a href="cat.html">BOOST_PP_CAT</a>(data, i))
<a href="set_for_each_i.html">BOOST_PP_SET_FOR_EACH_I</a>(MACRO, _, SET) // expands to a_0 b_1 c_2 d_3
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