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<html><head><title>boost::mpl::transform</title>
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<link rel="stylesheet" href="../mpl_wiki.css">
</head><body bgcolor="white">
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<h1><a href="../Table_of_Contents.html"><img src="../mpl_logo.jpg" alt="[Home]" border=0 align="right"></a>transform</h1><h3>Synopsis</h3>
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<p>
<pre>
template&lt;
typename Sequence
, typename Op
&gt;
struct transform
{
typedef <em>unspecified</em> type;
};
</pre>
<p>
<h3>Description</h3>
<p>
Performs a transformation on the sequence. The algorithm returns a new sequence produced by applying the unary metafunction <code>Op</code> to every element in the <code>[begin&lt;Sequence&gt;::type, end&lt;Sequence&gt;::type)</code> range. The result sequence preserves all the functional and performance characteristics of the original <code>Sequence</code>, including its size, but not identity.
<p>
<h3>Definition</h3>
<p>
<pre>
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#include "<a href="../../../../../boost/mpl/transform.hpp">boost/mpl/transform.hpp</a>"
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</pre>
<p>
<h3>Parameters</h3>
<table border="1">
<tr><th>&nbsp;Parameter&nbsp;</th><th>&nbsp;Requirement&nbsp;</th><th>&nbsp;Description &nbsp;</th></tr>
<tr><td><code>Sequence</code></td><td>A model of <a href="../Extensible_Sequence.html">Extensible Sequence</a></td><td>The original sequence. </td></tr>
<tr><td><code>Op</code></td><td>An unary [Lambda Expression]</td><td>A transformation. </td></tr>
</table>
<p>
<h3>Expression semantics</h3>
<p>
<table border="1">
<tr><th>&nbsp;Expression&nbsp;</th><th>&nbsp;Expression&nbsp;type&nbsp;</th><th>&nbsp;Precondition&nbsp;</th><th>&nbsp;Semantics&nbsp;</th><th>&nbsp;Postcondition&nbsp;</th></tr>
<tr><td><code>typedef transform&lt;Sequence,Op&gt;::type s;</code></td><td>A model of <a href="../Extensible_Sequence.html">Extensible Sequence</a></td><td></td><td></td><td><code>size&lt;s&gt;::type::value == size&lt;Sequence&gt;::type::value</code>. </td></tr>
</table>
<p>
<h3>Complexity</h3>
<p>
Linear. The operation <code>Op</code> is applied exactly <code><a href="../Reference/size.html">size</a>&lt;Sequence&gt;::type::value</code> times.
<p>
<h3>Example</h3>
<p>
<pre>
typedef <a href="../Reference/list.html">list</a>&lt;char,short,int,long,float,double&gt; types;
typedef <a href="../Reference/list.html">list</a>&lt;char*,short*,int*,long*,float*,double*&gt; pointers;
typedef transform&lt; types,boost::add_pointer&lt;_1&gt; &gt;::type result;
BOOST_STATIC_ASSERT((<a href="../Reference/equal.html">equal</a>&lt;result,pointers&gt;::value));
</pre>
<p>
<h3>See also</h3>
<p>
<a href="../Algorithms.html">Algorithms</a>, <code><a href="../Reference/replace.html">replace</a></code>, <code><a href="../Reference/replace_if.html">replace_if</a></code>, <code><a href="../Reference/transform.html">transform</a></code>
<p><hr>
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<a href="../Table_of_Contents.html">Table of Contents</a><br>Last edited July 17, 2002 5:47 am</body></html>