mirror of
https://github.com/boostorg/mpl.git
synced 2026-01-26 17:02:20 +01:00
60 lines
2.5 KiB
HTML
60 lines
2.5 KiB
HTML
<!doctype html public "-//ietf//dtd html//en">
|
|
<html><head><title>boost::mpl::count</title>
|
|
<link rel="stylesheet" href="../mpl_wiki.css">
|
|
</head><body bgcolor="white">
|
|
<h1><a href="../Table_of_Contents.html"><img src="../mpl_logo.jpg" alt="[Home]" border=0 align="right"></a>count</h1><h3>Synopsis</h3>
|
|
<p>
|
|
<pre>
|
|
template<
|
|
typename Sequence
|
|
, typename T
|
|
>
|
|
struct count
|
|
{
|
|
typedef <em>unspecified</em> type;
|
|
};
|
|
</pre>
|
|
<p>
|
|
<h3>Description</h3>
|
|
<p>
|
|
Returns the number of elements in a <code>Sequence</code> that are identical to <code>T</code>.
|
|
<p>
|
|
<h3>Definition</h3>
|
|
<p>
|
|
<pre>
|
|
#include "<a href="../../../../../boost/mpl/count.hpp">boost/mpl/count.hpp</a>"
|
|
</pre>
|
|
<p>
|
|
<h3>Parameters</h3>
|
|
<table border="1">
|
|
<tr><th> Parameter </th><th> Requirement </th><th> Description </th></tr>
|
|
<tr><td><code>Sequence</code></td><td>A model of <a href="../Forward_Sequence.html">Forward Sequence</a></td><td>A sequence to be examined. </td></tr>
|
|
<tr><td><code>T</code></td><td>A type</td><td>The type to be searched for. </td></tr>
|
|
</table>
|
|
<p>
|
|
<h3>Expression semantics</h3>
|
|
<p>
|
|
<table border="1">
|
|
<tr><th> Expression </th><th> Expression type </th><th> Precondition </th><th> Semantics </th><th> Postcondition </th></tr>
|
|
<tr><td><code>typedef count<Sequence,T>::type n;</code></td><td>A model of <a href="../Integral_Constant.html">Integral Constant</a></td><td></td><td>Equivalent to <code>typedef <a href="../Reference/count_if.html">count_if</a>< Sequence,is_same<_,T> >::type n;</code></td><td></td></tr>
|
|
</table>
|
|
<p>
|
|
<p>
|
|
<h3>Complexity</h3>
|
|
<p>
|
|
Linear. Exactly <code><a href="../Reference/size.html">size</a><Sequence>::value</code> comparisons for identity.
|
|
<p>
|
|
<h3>Example</h3>
|
|
<p>
|
|
<pre>
|
|
typedef <a href="../Reference/list.html">list</a><int,char,long,short,char,short,double,long> types;
|
|
typedef find<types, short>::type iter;
|
|
BOOST_STATIC_ASSERT((is_same<iter::type,short>::type::value));
|
|
BOOST_STATIC_ASSERT((<a href="../Reference/distance.html">distance</a>< begin<types>::type,iter >::type::value == 3));
|
|
</pre>
|
|
<p>
|
|
<h3>See also</h3>
|
|
<p>
|
|
<a href="../Algorithms.html">Algorithms</a>, <code><a href="../Reference/count_if.html">count_if</a></code>, <code><a href="../Reference/find.html">find</a></code>, <code><a href="../Reference/find_if.html">find_if</a></code>, <code><a href="../Reference/contains.html">contains</a></code>
|
|
<p><hr>
|
|
<a href="../Table_of_Contents.html">Table of Contents</a><br>Last edited December 12, 2002 2:05 am</body></html> |