3 <title>BOOST_PP_TUPLE_ELEM
</title>
4 <link rel=
"stylesheet" type=
"text/css" href=
"../styles.css">
7 <div style=
"margin-left: 0px;">
8 The
<b>BOOST_PP_TUPLE_ELEM
</b> macro extracts an element from a
<i>tuple
</i>.
12 <b>BOOST_PP_TUPLE_ELEM
</b>(
<i>size
</i>,
<i>i
</i>,
<i>tuple
</i>)
<sup></sup><br>
16 <b>BOOST_PP_TUPLE_ELEM
</b>(
<i>...
</i>)
<a href=
"../topics/variadic_macros.html#VNotation" target=
"_self"><sup>(v)
</sup></a><b></b><br>
22 The size of the
<i>tuple
</i>.
23 Valid
<i>tuple
</i> sizes range from
<i>1</i> to
<b>BOOST_PP_LIMIT_TUPLE
</b>.
27 The zero-based index into the
<i>tuple
</i> of the element to be extracted.
28 Valid values range from
<i>0</i> to
<i>size
</i> -
<i>1</i>.
32 The
<i>tuple
</i> from which an element is to be extracted.
37 The
<i>size
</i> argument must be the actual size of the
<i>tuple
</i>,
38 and
<i>i
</i> must be less than the size of the
<i>tuple
</i>.
<br>
40 invoke the variadic version as BOOST_PP_TUPLE_ELEM(
<i>i
</i>,
<i>tuple
</i>) or
41 BOOST_PP_TUPLE_ELEM(
<i>size
</i>,
<i>i
</i>,
<i>tuple
</i>).
45 <li><a href=
"limit_tuple.html">BOOST_PP_LIMIT_TUPLE
</a></li>
49 <b>Header:
</b> <a href=
"../headers/tuple/elem.html"><boost/preprocessor/tuple/elem.hpp
></a>
52 <div><pre>#include
<<a href=
"../headers/tuple/elem.html">boost/preprocessor/tuple/elem.hpp
</a>><br><br>#define TUPLE (a, b, c, d)
<br><br><a href=
"tuple_elem.html">BOOST_PP_TUPLE_ELEM
</a>(
4,
0, TUPLE) // expands to a
<br><a href=
"tuple_elem.html">BOOST_PP_TUPLE_ELEM
</a>(
4,
3, TUPLE) // expands to d
<br><br>// or for the variadic version
<a href=
"../topics/variadic_macros.html#VNotation" target=
"_self"><sup>(v)
</sup></a><br><br><a href=
"file:///C:/Programming/VersionControl/sandbox/variadics/libs/preprocessor/doc/ref/tuple_elem.html">BOOST_PP_TUPLE_ELEM
</a>(
0, TUPLE) // expands to a in the variadic version
<br><a href=
"file:///C:/Programming/VersionControl/sandbox/variadics/libs/preprocessor/doc/ref/tuple_elem.html">BOOST_PP_TUPLE_ELEM
</a>(
3, TUPLE) // expands to d in the variadic version
<br></pre></div>
54 <div style=
"margin-left: 0px;">
55 <i>© Copyright
<a href=
"http://www.housemarque.com" target=
"_top">Housemarque Oy
</a> 2002</i>
56 <br><i>© Copyright Paul Mensonides
2002<br>
57 </i><i>© Copyright Edward Diener
2011,
2013</i><br>
59 <div style=
"margin-left: 0px;">
60 <p><small>Distributed under the Boost Software License, Version
1.0. (See
61 accompanying file
<a href=
"../../../../LICENSE_1_0.txt">LICENSE_1_0.txt
</a> or
62 copy at
<a href=
"http://www.boost.org/LICENSE_1_0.txt">www.boost.org/LICENSE_1_0.txt
</a>)
</small></p>