3 <title>BOOST_PP_LIST_AT
</title>
4 <link rel=
"stylesheet" type=
"text/css" href=
"../styles.css">
7 <div style=
"margin-left: 0px;">
8 The
<b>BOOST_PP_LIST_AT
</b> macro extracts an element in a
<i>list
</i>.
12 <b>BOOST_PP_LIST_AT
</b>(
<i>list
</i>,
<i>index
</i>)
18 The
<i>list
</i> from which a element is to be extracted.
19 This
<i>list
</i> must have at least
<i>index
</i> +
<i>1</i> elements.
23 The zero-based position in the
<i>list
</i> of the element to be extracted.
28 Previously, this macro could not be used inside
<b>BOOST_PP_WHILE
</b>.
29 There is no longer any such restriction.
30 It is more efficient, however, to use
<b>BOOST_PP_LIST_AT_D
</b> in such a situation.
34 <li><a href=
"list_at_d.html">BOOST_PP_LIST_AT_D
</a></li>
38 <b>Header:
</b> <a href=
"../headers/list/at.html"><boost/preprocessor/list/at.hpp
></a>
42 #include
<<a href=
"../headers/list/at.html">boost/preprocessor/list/at.hpp
</a>>
44 #define LIST (a, (b, (c,
<a href=
"nil.html">BOOST_PP_NIL
</a>)))
46 <a href=
"list_at.html">BOOST_PP_LIST_AT
</a>(LIST,
0) // expands to a
47 <a href=
"list_at.html">BOOST_PP_LIST_AT
</a>(LIST,
2) // expands to c
50 <div style=
"margin-left: 0px;">
51 <i>© Copyright
<a href=
"http://www.housemarque.com" target=
"_top">Housemarque Oy
</a> 2002</i>
52 </br><i>© Copyright Paul Mensonides
2002</i>
54 <div style=
"margin-left: 0px;">
55 <p><small>Distributed under the Boost Software License, Version
1.0. (See
56 accompanying file
<a href=
"../../../../LICENSE_1_0.txt">LICENSE_1_0.txt
</a> or
58 "http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt
</a>)
</small></p>