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: BOOST_MPL_ASSERT_NOT</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="./assert-msg.html" class="navigation-link">Prev</a> <a href="./assert-relation.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./assert-msg.html" class="navigation-link">Back</a> <a href="./assert-relation.html" class="navigation-link">Along</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./asserts.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> 12<td class="header-group page-location"><a href="../refmanual.html" class="navigation-link">Front Page</a> / <a href="./macros.html" class="navigation-link">Macros</a> / <a href="./asserts.html" class="navigation-link">Asserts</a> / <a href="./assert-not.html" class="navigation-link">BOOST_MPL_ASSERT_NOT</a></td> 13</tr></table><div class="header-separator"></div> 14<div class="section" id="boost-mpl-assert-not"> 15<h1><a class="toc-backref" href="./asserts.html#id1590">BOOST_MPL_ASSERT_NOT</a></h1> 16<div class="section" id="id1301"> 17<h3><a class="subsection-title" href="#synopsis" name="synopsis">Synopsis</a></h3> 18<pre class="literal-block"> 19#define <a href="./assert-not.html" class="identifier">BOOST_MPL_ASSERT_NOT</a>( pred ) \ 20 <em>unspecified token sequence</em> \ 21/**/ 22</pre> 23</div> 24<div class="section" id="id1302"> 25<h3><a class="subsection-title" href="#description" name="description">Description</a></h3> 26<p>Generates a compilation error when predicate holds true.</p> 27</div> 28<div class="section" id="id1303"> 29<h3><a class="subsection-title" href="#header" name="header">Header</a></h3> 30<pre class="literal-block"> 31#include <<a href="../../../../boost/mpl/assert.hpp" class="header">boost/mpl/assert.hpp</a>> 32</pre> 33</div> 34<div class="section" id="id1304"> 35<h3><a class="subsection-title" href="#parameters" name="parameters">Parameters</a></h3> 36<table border="1" class="docutils table"> 37<colgroup> 38<col width="16%" /> 39<col width="38%" /> 40<col width="46%" /> 41</colgroup> 42<thead valign="bottom"> 43<tr><th class="head">Parameter</th> 44<th class="head">Requirement</th> 45<th class="head">Description</th> 46</tr> 47</thead> 48<tbody valign="top"> 49<tr><td><tt class="literal"><span class="pre">pred</span></tt></td> 50<td>Boolean nullary <a class="reference internal" href="./metafunction.html">Metafunction</a></td> 51<td>A predicate to be asserted to be false.</td> 52</tr> 53</tbody> 54</table> 55</div> 56<div class="section" id="id1305"> 57<h3><a class="subsection-title" href="#expression-semantics" name="expression-semantics">Expression semantics</a></h3> 58<p>For any boolean nullary <a class="reference internal" href="./metafunction.html">Metafunction</a> <tt class="literal"><span class="pre">pred</span></tt>:</p> 59<pre class="literal-block"> 60<a href="./assert-not.html" class="identifier">BOOST_MPL_ASSERT_NOT</a>(( pred )); 61</pre> 62<table class="docutils field-list" frame="void" rules="none"> 63<col class="field-name" /> 64<col class="field-body" /> 65<tbody valign="top"> 66<tr class="field"><th class="field-name">Return type:</th><td class="field-body"><p class="first">None.</p> 67</td> 68</tr> 69<tr class="field"><th class="field-name">Semantics:</th><td class="field-body"><p class="first">Generates a compilation error if <tt class="literal"><span class="pre">pred::type::value</span> <span class="pre">!=</span> <span class="pre">false</span></tt>, otherwise 70has no effect. Note that double parentheses are required even if no commas 71appear in the condition.</p> 72<p>When possible within the compiler's diagnostic capabilities, 73the error message will include the predicate's full type name, and have a 74general form of:</p> 75<pre class="last literal-block"> 76<em>...</em> ************boost::mpl::<a href="./not.html" class="identifier">not_</a>< pred >::************ <em>...</em> 77</pre> 78</td> 79</tr> 80</tbody> 81</table> 82</div> 83<div class="section" id="id1306"> 84<h3><a class="subsection-title" href="#example" name="example">Example</a></h3> 85<pre class="literal-block"> 86template< typename T, typename U > struct my 87{ 88 // ... 89 <a href="./assert-not.html" class="identifier">BOOST_MPL_ASSERT_NOT</a>(( is_same< T,U > )); 90}; 91 92my<void,void> test; 93 94// In instantiation of `my<void, void>': 95// instantiated from here 96// conversion from ` 97// mpl_::failed************boost::mpl::<a href="./not.html" class="identifier">not_</a><boost::is_same<void, void> 98// >::************' to non-scalar type `mpl_::assert<false>' requested 99</pre> 100</div> 101<div class="section" id="id1307"> 102<h3><a class="subsection-title" href="#see-also" name="see-also">See also</a></h3> 103<p><a class="reference internal" href="./asserts.html">Asserts</a>, <a class="reference internal" href="./assert.html">BOOST_MPL_ASSERT</a>, <a class="reference internal" href="./assert-msg.html">BOOST_MPL_ASSERT_MSG</a>, <a class="reference internal" href="./assert-relation.html">BOOST_MPL_ASSERT_RELATION</a></p> 104<!-- Macros/Asserts//BOOST_MPL_ASSERT_RELATION --> 105</div> 106</div> 107 108<div class="footer-separator"></div> 109<table class="footer"><tr class="footer"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./assert-msg.html" class="navigation-link">Prev</a> <a href="./assert-relation.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./assert-msg.html" class="navigation-link">Back</a> <a href="./assert-relation.html" class="navigation-link">Along</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./asserts.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> 110<td><div class="copyright-footer"><div class="copyright">Copyright © 2001-2009 Aleksey Gurtovoy and David Abrahams</div> 111Distributed under the Boost Software License, Version 1.0. (See accompanying 112file 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> 113</html> 114