<?xml version="1.0" encoding="utf-8" ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <meta name="generator" content="Docutils 0.7: http://docutils.sourceforge.net/" /> <title>The MPL Reference Manual: Random Access Sequence</title> <link rel="stylesheet" href="../style.css" type="text/css" /> </head> <body class="docframe refmanual"> <table class="header"><tr class="header"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./bidirectional-sequence.html" class="navigation-link">Prev</a> <a href="./extensible-sequence.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./bidirectional-sequence.html" class="navigation-link">Back</a> <a href="./extensible-sequence.html" class="navigation-link">Along</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./concepts.html" class="navigation-link">Up</a> <a href="../refmanual.html" class="navigation-link">Home</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./refmanual_toc.html" class="navigation-link">Full TOC</a></span></td> <td class="header-group page-location"><a href="../refmanual.html" class="navigation-link">Front Page</a> / <a href="./sequences.html" class="navigation-link">Sequences</a> / <a href="./concepts.html" class="navigation-link">Concepts</a> / <a href="./random-access-sequence.html" class="navigation-link">Random Access Sequence</a></td> </tr></table><div class="header-separator"></div> <div class="section" id="random-access-sequence"> <h1><a class="toc-backref" href="./concepts.html#id1397">Random Access Sequence</a></h1> <div class="section" id="id6"> <h3><a class="subsection-title" href="#description" name="description">Description</a></h3> <p>A <a class="reference internal" href="./random-access-sequence.html">Random Access Sequence</a> is a <a class="reference internal" href="./bidirectional-sequence.html">Bidirectional Sequence</a> whose iterators model <a class="reference internal" href="./random-access-iterator.html">Random Access Iterator</a>. A random access sequence guarantees amortized constant time access to an arbitrary sequence element.</p> </div> <div class="section" id="id7"> <h3><a class="subsection-title" href="#refinement-of" name="refinement-of">Refinement of</a></h3> <p><a class="reference internal" href="./bidirectional-sequence.html">Bidirectional Sequence</a></p> </div> <div class="section" id="id8"> <h3><a class="subsection-title" href="#expression-requirements" name="expression-requirements">Expression requirements</a></h3> <p>In addition to the requirements defined in <a class="reference internal" href="./bidirectional-sequence.html">Bidirectional Sequence</a>, for any <a class="reference internal" href="./random-access-sequence.html">Random Access Sequence</a> <tt class="literal"><span class="pre">s</span></tt> the following must be met:</p> <table border="1" class="docutils table"> <colgroup> <col width="30%" /> <col width="39%" /> <col width="30%" /> </colgroup> <thead valign="bottom"> <tr><th class="head">Expression</th> <th class="head">Type</th> <th class="head">Complexity</th> </tr> </thead> <tbody valign="top"> <tr><td><tt class="literal"><span class="pre"><a href="./begin.html" class="identifier">begin</a><s>::type</span></tt></td> <td><a class="reference internal" href="./random-access-iterator.html">Random Access Iterator</a></td> <td>Amortized constant time</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./end.html" class="identifier">end</a><s>::type</span></tt></td> <td><a class="reference internal" href="./random-access-iterator.html">Random Access Iterator</a></td> <td>Amortized constant time</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./at.html" class="identifier">at</a><s,n>::type</span></tt></td> <td>Any type</td> <td>Amortized constant time</td> </tr> </tbody> </table> </div> <div class="section" id="id9"> <h3><a class="subsection-title" href="#expression-semantics" name="expression-semantics">Expression semantics</a></h3> <p>Semantics of an expression is defined only where it differs from, or is not defined in <a class="reference internal" href="./bidirectional-sequence.html">Bidirectional Sequence</a>.</p> <table border="1" class="docutils table"> <colgroup> <col width="28%" /> <col width="72%" /> </colgroup> <thead valign="bottom"> <tr><th class="head">Expression</th> <th class="head">Semantics</th> </tr> </thead> <tbody valign="top"> <tr><td><tt class="literal"><span class="pre"><a href="./at.html" class="identifier">at</a><s,n>::type</span></tt></td> <td>The <tt class="literal"><span class="pre">n</span></tt>th element from the beginning of the sequence; see <a class="reference internal" href="./at.html">at</a>.</td> </tr> </tbody> </table> </div> <div class="section" id="id10"> <h3><a class="subsection-title" href="#models" name="models">Models</a></h3> <ul class="simple"> <li><a class="reference internal" href="./vector.html">vector</a></li> <li><a class="reference internal" href="./range-c.html">range_c</a></li> </ul> </div> <div class="section" id="id11"> <h3><a class="subsection-title" href="#see-also" name="see-also">See also</a></h3> <p><a class="reference internal" href="./sequences.html">Sequences</a>, <a class="reference internal" href="./bidirectional-sequence.html">Bidirectional Sequence</a>, <a class="reference internal" href="./extensible-sequence.html">Extensible Sequence</a>, <a class="reference internal" href="./random-access-iterator.html">Random Access Iterator</a>, <a class="reference internal" href="./begin.html">begin</a> / <a class="reference internal" href="./end.html">end</a>, <a class="reference internal" href="./at.html">at</a></p> <!-- Sequences/Concepts//Extensible Sequence |40 --> </div> </div> <div class="footer-separator"></div> <table class="footer"><tr class="footer"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./bidirectional-sequence.html" class="navigation-link">Prev</a> <a href="./extensible-sequence.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./bidirectional-sequence.html" class="navigation-link">Back</a> <a href="./extensible-sequence.html" class="navigation-link">Along</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./concepts.html" class="navigation-link">Up</a> <a href="../refmanual.html" class="navigation-link">Home</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./refmanual_toc.html" class="navigation-link">Full TOC</a></span></td> <td><div class="copyright-footer"><div class="copyright">Copyright © 2001-2009 Aleksey Gurtovoy and David Abrahams</div> Distributed under the Boost Software License, Version 1.0. 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