<!--
    Licensed to the Apache Software  Foundation (ASF) under one or more
    contributor  license agreements.  See  the NOTICE  file distributed
    with  this  work  for  additional information  regarding  copyright
    ownership.   The ASF  licenses this  file to  you under  the Apache
    License, Version  2.0 (the  License); you may  not use  this file
    except in  compliance with the License.   You may obtain  a copy of
    the License at

    http://www.apache.org/licenses/LICENSE-2.0

    Unless required by applicable law or agreed to in writing, software
    distributed under the  License is distributed on an  "AS IS" BASIS,
    WITHOUT  WARRANTIES OR CONDITIONS  OF ANY  KIND, either  express or
    implied.   See  the License  for  the  specific language  governing
    permissions and limitations under the License.

    Copyright 1999-2007 Rogue Wave Software, Inc.
-->

<HTML>
<HEAD>
<TITLE>adjacent_find()</TITLE>
<LINK REL=StyleSheet HREF="../rw.css" TYPE="text/css" TITLE="Apache stdcxx Stylesheet"></HEAD>
<BODY BGCOLOR=#FFFFFF>
<A HREF="adjacent-difference.html"><IMG SRC="images/bprev.gif" WIDTH=20 HEIGHT=21 ALT="Previous file" BORDER=O></A><A HREF="noframes.html"><IMG SRC="images/btop.gif" WIDTH=56 HEIGHT=21 ALT="Top of Document" BORDER=O></A><A HREF="booktoc.html"><IMG SRC="images/btoc.gif" WIDTH=56 HEIGHT=21 ALT="Contents" BORDER=O></A><A HREF="tindex.html"><IMG SRC="images/bindex.gif" WIDTH=56 HEIGHT=21 ALT="Index page" BORDER=O></A><A HREF="advance.html"><IMG SRC="images/bnext.gif" WIDTH=25 HEIGHT=21 ALT="Next file" BORDER=O></A><DIV CLASS="DOCUMENTNAME"><B>Apache C++ Standard Library Reference Guide</B></DIV>
<H2>adjacent_find()</H2>
<P><B>Library:</B>&nbsp;&nbsp;<A HREF="2-9.html">Algorithms</A></P>

<PRE><HR><B><I>Function</I></B><HR></PRE>

<UL>
<LI><A HREF="#sec1">Local Index</A></LI>
<LI><A HREF="#sec2">Summary</A></LI>
<LI><A HREF="#sec3">Synopsis</A></LI>
<LI><A HREF="#sec4">Description</A></LI>
<LI><A HREF="#sec5">Complexity</A></LI>
<LI><A HREF="#sec6">Example</A></LI>
<LI><A HREF="#sec7">See Also</A></LI>
<LI><A HREF="#sec8">Standards Conformance</A></LI>
</UL>
<A NAME="sec1"><H3>Local Index</H3></A>
No Entries
<A NAME="sec2"><H3>Summary</H3></A>
<P>An algorithm that finds the first adjacent pair of equivalent elements in a sequence</P>
<A NAME="sec3"><H3>Synopsis</H3></A>

<PRE>#include &lt;algorithm&gt;

namespace std {
  template &lt;class ForwardIterator&gt;
    ForwardIterator
    adjacent_find(ForwardIterator start, 
                  ForwardIterator finish);

  template &lt;class ForwardIterator, class BinaryPredicate&gt;
    ForwardIterator
    adjacent_find(ForwardIterator start, <br>                  ForwardIterator finish,
                  BinaryPredicate binary_pred);
}
</PRE>
<A NAME="sec4"><H3>Description</H3></A>
<P>There are two variations of the <SAMP>adjacent_find()</SAMP> algorithm. The first finds equal adjacent elements in the sequence defined by iterators <SAMP>start</SAMP> and <SAMP>finish</SAMP> and returns an iterator <SAMP>i</SAMP> pointing to the first of the equal elements. The second variation lets you specify a binary function object to test for a condition. The algorithm returns an iterator <SAMP>i</SAMP> pointing to the first of the pair of elements that meet the conditions of the binary function. In other words, <SAMP>adjacent_find()</SAMP> returns the first iterator <SAMP>i</SAMP> where both <SAMP>i</SAMP> and <SAMP>i + 1</SAMP> are in the range <SAMP>[start, finish)</SAMP> that meets one of the following conditions:</P>
<P><SAMP>*i == *(i + 1)</SAMP></P>
<P>or</P>
<P><SAMP>binary_pred(*i,*(i + 1)) == true</SAMP></P>
<P>If <SAMP>adjacent_find()</SAMP> does not find a match, it returns <SAMP>finish</SAMP>.</P>
<A NAME="sec5"><H3>Complexity</H3></A>
<P><SAMP>adjacent_find()</SAMP> performs exactly <SAMP>find(start,finish,value) - start</SAMP> applications of the corresponding predicate.</P>
<A NAME="sec6"><H3>Example</H3></A>

<UL><PRE>//
//  find.cpp
//

#include &lt;vector&gt;      // for vector
#include &lt;algorithm&gt;   // for adjacent_find, find
#include &lt;functional&gt;  // for bind1st, equal_to
#include &lt;iostream&gt;    // for cout, endl


int main ()
{
    // Typedef for convenience.
    typedef std::vector&lt;int, std::allocator&lt;int&gt; &gt; Vector;

    const Vector::value_type arr[] = { 0, 1, 2, 2, 3, 
                                       4, 2, 2, 6, 7 };

    // Set up a vector.
    const Vector v1 (arr, arr + sizeof arr / sizeof *arr);

    // Try find.
    Vector::const_iterator it = std::find (v1.begin (), 
                                           v1.end (), 3);

    std::cout &lt;&lt; *it &lt;&lt; ' ';

    // Try find_if.
    it = std::find_if (v1.begin (), v1.end (),
             std::bind1st (std::equal_to&lt;Vector::value_type&gt;(), 
             3));

    std::cout &lt;&lt; *it &lt;&lt; ' ';

    // Try both adjacent_find variants.
    it = std::adjacent_find (v1.begin (), v1.end ());

    std::cout &lt;&lt; *it &lt;&lt; ' ';

    it = std::adjacent_find (v1.begin (), v1.end (),
                          std::equal_to&lt;Vector::value_type&gt;());

    std::cout &lt;&lt; *it &lt;&lt; std::endl;

    return 0;
}


Program Output:
</PRE></UL>
<UL><PRE>3 3 2 2
</PRE></UL>
<A NAME="sec7"><H3>See Also</H3></A>
<P><SAMP><A HREF="find.html">find()</A></SAMP></P>
<A NAME="sec8"><H3>Standards Conformance</H3></A>
<P><I>ISO/IEC 14882:1998 -- International Standard for Information Systems -- Programming Language C++, Section 25.1.5</I></P>

<BR>
<HR>
<A HREF="adjacent-difference.html"><IMG SRC="images/bprev.gif" WIDTH=20 HEIGHT=21 ALT="Previous file" BORDER=O></A><A HREF="noframes.html"><IMG SRC="images/btop.gif" WIDTH=56 HEIGHT=21 ALT="Top of Document" BORDER=O></A><A HREF="booktoc.html"><IMG SRC="images/btoc.gif" WIDTH=56 HEIGHT=21 ALT="Contents" BORDER=O></A><A HREF="tindex.html"><IMG SRC="images/bindex.gif" WIDTH=56 HEIGHT=21 ALT="Index page" BORDER=O></A><A HREF="advance.html"><IMG SRC="images/bnext.gif" WIDTH=20 HEIGHT=21 ALT="Next file" BORDER=O></A>

<!-- Google Analytics tracking code -->
<script src="http://www.google-analytics.com/urchin.js" type="text/javascript">
</script>
<script type="text/javascript">
    _uacct = "UA-1775151-1";
    urchinTracker();
</script>
<!-- end of Google Analytics tracking code -->

</BODY>
</HTML>