2002-10-13 05:47:23 +00:00
|
|
|
<html>
|
2002-11-07 23:39:29 +00:00
|
|
|
<head>
|
|
|
|
|
<title>BOOST_PP_SEQ_FOLD_LEFT_s</title>
|
|
|
|
|
<link rel="stylesheet" type="text/css" href="../styles.css">
|
|
|
|
|
</head>
|
|
|
|
|
<body>
|
|
|
|
|
<div style="margin-left: 0px;">
|
|
|
|
|
The <b>BOOST_PP_SEQ_FOLD_LEFT_<i>s</i></b> macro folds (or accumulates) the
|
|
|
|
|
elements of a <i>seq</i> left-to-right. It reenters <b>BOOST_PP_SEQ_FOLD_LEFT</b>
|
|
|
|
|
with maximum efficiency.
|
|
|
|
|
</div>
|
|
|
|
|
<h4>
|
|
|
|
|
Usage
|
|
|
|
|
</h4>
|
2002-10-13 05:47:23 +00:00
|
|
|
<div class="code">
|
2002-11-07 23:39:29 +00:00
|
|
|
<b>BOOST_PP_SEQ_FOLD_LEFT_</b> ## <i>s</i>(<i>op</i>, <i>state</i>, <i>seq</i>)
|
2002-10-13 05:47:23 +00:00
|
|
|
</div>
|
2002-11-07 23:39:29 +00:00
|
|
|
<h4>
|
|
|
|
|
Arguments
|
|
|
|
|
</h4>
|
2002-10-13 05:47:23 +00:00
|
|
|
<dl>
|
|
|
|
|
<dt>s</dt>
|
|
|
|
|
<dd>
|
2002-11-07 23:39:29 +00:00
|
|
|
The next available <b>BOOST_PP_SEQ_FOLD_LEFT</b> fold step.
|
2002-10-13 05:47:23 +00:00
|
|
|
</dd>
|
|
|
|
|
<dt>op</dt>
|
|
|
|
|
<dd>
|
2002-11-07 23:39:29 +00:00
|
|
|
A ternary operation of the form <i>op</i>(<i>s</i>, <i>state</i>, <i>elem</i>).
|
|
|
|
|
This macro is called for each element in <i>seq</i>--each time returning a new <i>state</i>.
|
|
|
|
|
This operation is expanded by <b>BOOST_PP_SEQ_FOLD_LEFT</b> with the next
|
|
|
|
|
available fold step, the current <i>state</i>, and the current element.
|
2002-10-13 05:47:23 +00:00
|
|
|
</dd>
|
|
|
|
|
<dt>state</dt>
|
|
|
|
|
<dd>
|
|
|
|
|
The initial state of the fold.
|
|
|
|
|
</dd>
|
2002-11-07 23:39:29 +00:00
|
|
|
<dt>seq</dt>
|
2002-10-13 05:47:23 +00:00
|
|
|
<dd>
|
2002-11-07 23:39:29 +00:00
|
|
|
The <i>seq</i> to be folded.
|
2002-10-13 05:47:23 +00:00
|
|
|
</dd>
|
|
|
|
|
</dl>
|
2002-11-07 23:39:29 +00:00
|
|
|
<h4>
|
|
|
|
|
Remarks
|
|
|
|
|
</h4>
|
2002-10-13 05:47:23 +00:00
|
|
|
<div>
|
2002-11-07 23:39:29 +00:00
|
|
|
For the <i>seq</i>, (<i>0</i>)(<i>1</i>)(<i>2</i>), this macro expands to:
|
2002-10-13 05:47:23 +00:00
|
|
|
<div>
|
2002-11-07 23:39:29 +00:00
|
|
|
<i>op</i>(<i>s</i>, <i>op</i>(<i>s</i>, <i>op</i>(<i>s</i>, <i>state</i>, <i>0</i>),
|
|
|
|
|
<i>1</i>), <i>2</i>)
|
2002-10-13 05:47:23 +00:00
|
|
|
</div>
|
|
|
|
|
</div>
|
2002-11-07 23:39:29 +00:00
|
|
|
<h4>
|
|
|
|
|
See Also
|
|
|
|
|
</h4>
|
2002-10-13 05:47:23 +00:00
|
|
|
<ul>
|
2002-11-07 23:39:29 +00:00
|
|
|
<li>
|
|
|
|
|
<a href="seq_fold_left.html">BOOST_PP_SEQ_FOLD_LEFT</a></li>
|
2002-10-13 05:47:23 +00:00
|
|
|
</ul>
|
2002-11-07 23:39:29 +00:00
|
|
|
<h4>
|
|
|
|
|
Requirements
|
|
|
|
|
</h4>
|
2002-10-13 05:47:23 +00:00
|
|
|
<div>
|
2002-11-07 23:39:29 +00:00
|
|
|
<b>Header:</b> <a href="../headers/seq/fold_left.hpp.html"><boost/preprocessor/seq/fold_left.hpp></a>
|
2002-10-13 05:47:23 +00:00
|
|
|
</div>
|
2002-11-07 23:39:29 +00:00
|
|
|
<h4>
|
|
|
|
|
Sample Code
|
|
|
|
|
</h4>
|
|
|
|
|
<div>
|
|
|
|
|
<pre>
|
2002-10-13 05:47:23 +00:00
|
|
|
#include <<a href="../headers/cat.hpp.html">boost/preprocessor/cat.hpp</a>>
|
2002-11-07 23:39:29 +00:00
|
|
|
#include <<a href="../headers/seq/fold_left.hpp.html">boost/preprocessor/seq/fold_left.hpp</a>>
|
|
|
|
|
#include <<a href="../headers/seq/seq.hpp.html">boost/preprocessor/seq/seq.hpp</a>>
|
2002-10-13 05:47:23 +00:00
|
|
|
|
|
|
|
|
#define S1 (a)(b)(c)
|
|
|
|
|
#define S2 (S1)(S1)(S1)
|
|
|
|
|
|
2002-11-07 23:39:29 +00:00
|
|
|
#define OP(s, state, x) state (<a href="seq_fold_left_s.html">BOOST_PP_SEQ_FOLD_LEFT_</a> ## s(OP_2, _, x))
|
2002-10-13 05:47:23 +00:00
|
|
|
#define OP_2(s, state, x) <a href="cat.html">BOOST_PP_CAT</a>(state, x)
|
|
|
|
|
|
2002-11-07 23:39:29 +00:00
|
|
|
<a href="seq_fold_left.html">BOOST_PP_SEQ_FOLD_LEFT</a>(OP, <a href="seq_nil.html">BOOST_PP_SEQ_NIL</a>, S2)
|
2002-10-13 05:47:23 +00:00
|
|
|
// expands to (_abc)(_abc)(_abc)
|
2002-11-07 23:39:29 +00:00
|
|
|
</pre>
|
|
|
|
|
</div>
|
|
|
|
|
</body>
|
2002-10-13 05:47:23 +00:00
|
|
|
</html>
|
