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- <title>BOOST_PP_LIST_FOLD_LEFT_2ND</title>
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- The <b>BOOST_PP_LIST_FOLD_LEFT_2ND</b> macro folds (or accumulates) the elements of a <i>list</i> left-to-right.
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- <h4>Usage</h4>
- <div class="code">
- <b>BOOST_PP_LIST_FOLD_LEFT_2ND</b>(<i>op</i>, <i>state</i>, <i>list</i>)
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- <h4>Arguments</h4>
- <dl>
- <dt>op</dt>
- <dd>
- A ternary operation of the form <i>op</i>(<i>d</i>, <i>state</i>, <i>elem</i>).
- This macro is called for each element in <i>list</i>--each time returning a new <i>state</i>.
- This operation is expanded by <b>BOOST_PP_LIST_FOLD_LEFT</b> with the next available <b>BOOST_PP_WHILE</b> iteration,
- the current <i>state</i>, and the current element.
- </dd>
- <dt>state</dt>
- <dd>
- The initial state of the fold.
- </dd>
- <dt>list</dt>
- <dd>
- The <i>list</i> to be folded.
- </dd>
- </dl>
- <h4>Remarks</h4>
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- For the <i>list</i>, (<i>0</i>, (<i>1</i>, (<i>2</i>, <b>BOOST_PP_NIL</b>))), this macro expands to:
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- <i>op</i>(<i>d</i>, <i>op</i>(<i>d</i>, <i>op</i>(<i>d</i>, <i>state</i>, <i>0</i>), <i>1</i>), <i>2</i>)
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- </div>
- <div>
- This macro is deprecated.
- Use <b>BOOST_PP_LIST_FOLD_LEFT_<i>d</i></b> instead.
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- <h4>See Also</h4>
- <ul>
- <li><a href="list_fold_left.html">BOOST_PP_LIST_FOLD_LEFT</a></li>
- <li><a href="list_fold_left_d.html">BOOST_PP_LIST_FOLD_LEFT_<i>d</i></a></li>
- </ul>
- <h4>Requirements</h4>
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- <b>Header:</b> <a href="../headers/list/fold_left.html"><boost/preprocessor/list/fold_left.hpp></a>
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- <h4>Sample Code</h4>
- <div><pre>
- #include <<a href="../headers/cat.html">boost/preprocessor/cat.hpp</a>>
- #include <<a href="../headers/list/fold_left.html">boost/preprocessor/list/fold_left.hpp</a>>
- #define LIST (a, (b, (c, <a href="nil.html">BOOST_PP_NIL</a>)))
- #define OP(d, state, x) <a href="cat.html">BOOST_PP_CAT</a>(state, x)
- <a href="list_fold_left_2nd.html">BOOST_PP_LIST_FOLD_LEFT_2ND</a>(OP, _, LIST) // expands to _abc
- </pre></div>
- <hr size="1">
- <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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