1<?xml version="1.0" encoding="utf-8" ?> 2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 3<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> 4<head> 5<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 6<meta name="generator" content="Docutils 0.7: http://docutils.sourceforge.net/" /> 7<title>The MPL Reference Manual: Lambda Expression</title> 8<link rel="stylesheet" href="../style.css" type="text/css" /> 9</head> 10<body class="docframe refmanual"> 11<table class="header"><tr class="header"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./metafunction-class.html" class="navigation-link">Prev</a> <a href="./placeholder-expression.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./metafunction-class.html" class="navigation-link">Back</a> <a 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Expression</a></h1> 16<div class="section" id="id831"> 17<h3><a class="subsection-title" href="#description" name="description">Description</a></h3> 18<p>A <a class="reference internal" href="./lambda-expression.html">Lambda Expression</a> is a compile-time invocable entity in either of the following two 19forms:</p> 20<ul class="simple"> 21<li><a class="reference internal" href="./metafunction-class.html">Metafunction Class</a></li> 22<li><a class="reference internal" href="./placeholder-expression.html">Placeholder Expression</a></li> 23</ul> 24<p>Most of the MPL components accept either of those, and the concept 25gives us a consice way to describe these requirements.</p> 26</div> 27<div class="section" id="id832"> 28<h3><a class="subsection-title" href="#expression-requirements" name="expression-requirements">Expression requirements</a></h3> 29<p>See corresponding <a class="reference internal" href="./metafunction-class.html">Metafunction Class</a> and <a class="reference internal" href="./placeholder-expression.html">Placeholder Expression</a> specifications.</p> 30</div> 31<div class="section" id="id833"> 32<h3><a class="subsection-title" href="#models" name="models">Models</a></h3> 33<ul class="simple"> 34<li><a class="reference internal" href="./always.html">always</a></li> 35<li><a class="reference internal" href="./unpack-args.html">unpack_args</a></li> 36<li><tt class="literal"><span class="pre"><a href="./plus.html" class="identifier">plus</a><_,</span> <span class="pre"><a href="./int.html" class="identifier">int_</a><2></span> <span class="pre">></span></tt></li> 37<li><tt class="literal"><span class="pre"><a href="./if.html" class="identifier">if_</a><</span> <span class="pre"><a href="./less.html" class="identifier">less</a><<a href="./placeholders.html" class="identifier">_1</a>,</span> <span class="pre"><a href="./int.html" class="identifier">int_</a><7></span> <span class="pre">>,</span> <span class="pre"><a href="./plus.html" class="identifier">plus</a><<a href="./placeholders.html" class="identifier">_1</a>,<a href="./placeholders.html" class="identifier">_2</a>>,</span> <span class="pre"><a href="./placeholders.html" class="identifier">_1</a></span> <span class="pre">></span></tt></li> 38</ul> 39</div> 40<div class="section" id="id834"> 41<h3><a class="subsection-title" href="#see-also" name="see-also">See also</a></h3> 42<p><a class="reference internal" href="./metafunctions.html">Metafunctions</a>, <a class="reference internal" href="./placeholders.html">Placeholders</a>, <a class="reference internal" href="./apply.html">apply</a>, <a class="reference internal" href="./lambda.html">lambda</a></p> 43<!-- Metafunctions/Concepts//Placeholder Expression |40 --> 44</div> 45</div> 46 47<div class="footer-separator"></div> 48<table class="footer"><tr class="footer"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./metafunction-class.html" class="navigation-link">Prev</a> <a href="./placeholder-expression.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./metafunction-class.html" class="navigation-link">Back</a> <a href="./placeholder-expression.html" class="navigation-link">Along</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./metafunctions-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> 49<td><div class="copyright-footer"><div class="copyright">Copyright © 2001-2009 Aleksey Gurtovoy and David Abrahams</div> 50Distributed under the Boost Software License, Version 1.0. (See accompanying 51file LICENSE_1_0.txt or copy at <a class="reference external" href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)</div></td></tr></table></body> 52</html> 53