1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2<html> 3<head> 4<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 5<title>Struct template uses_allocator</title> 6<link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css"> 7<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 8<link rel="home" href="../../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> 9<link rel="up" href="../../boost_container_header_reference.html#header.boost.container.uses_allocator_hpp" title="Header <boost/container/uses_allocator.hpp>"> 10<link rel="prev" href="construc_idm45641208064992.html" title="Struct template constructible_with_allocator_suffix"> 11<link rel="next" href="erased_type.html" title="Struct erased_type"> 12</head> 13<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 14<table cellpadding="2" width="100%"><tr> 15<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../boost.png"></td> 16<td align="center"><a href="../../../../index.html">Home</a></td> 17<td align="center"><a href="../../../../libs/libraries.htm">Libraries</a></td> 18<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 19<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 20<td align="center"><a href="../../../../more/index.htm">More</a></td> 21</tr></table> 22<hr> 23<div class="spirit-nav"> 24<a accesskey="p" href="construc_idm45641208064992.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../boost_container_header_reference.html#header.boost.container.uses_allocator_hpp"><img src="../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="erased_type.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 25</div> 26<div class="refentry"> 27<a name="boost.container.uses_allocator"></a><div class="titlepage"></div> 28<div class="refnamediv"> 29<h2><span class="refentrytitle">Struct template uses_allocator</span></h2> 30<p>boost::container::uses_allocator</p> 31</div> 32<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 33<div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: <<a class="link" href="../../boost_container_header_reference.html#header.boost.container.uses_allocator_hpp" title="Header <boost/container/uses_allocator.hpp>">boost/container/uses_allocator.hpp</a>> 34 35</span><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">,</span> <span class="keyword">typename</span> Allocator<span class="special">></span> 36<span class="keyword">struct</span> <a class="link" href="uses_allocator.html" title="Struct template uses_allocator">uses_allocator</a> <span class="special">:</span> <span class="keyword">public</span> <span class="identifier">dtl</span><span class="special">::</span><span class="identifier">uses_allocator_imp</span><span class="special"><</span> <span class="identifier">T</span><span class="special">,</span> <span class="identifier">Allocator</span> <span class="special">></span> <span class="special">{</span> 37<span class="special">}</span><span class="special">;</span></pre></div> 38<div class="refsect1"> 39<a name="id-1.3.10.14.42.5.4"></a><h2>Description</h2> 40<p><span class="bold"><strong>Remark</strong></span>: Automatically detects whether T has a nested allocator_type that is convertible from Allocator. Meets the BinaryTypeTrait requirements ([meta.rqmts] 20.4.1). A program may specialize this type to define uses_allocator<X>::value as true for a T of user-defined type if T does not have a nested allocator_type but is nonetheless constructible using the specified Allocator where either: the first argument of a constructor has type allocator_arg_t and the second argument has type Alloc or the last argument of a constructor has type Alloc.</p> 41<p><span class="bold"><strong>Result</strong></span>: uses_allocator<T, Allocator>::value== true if a type T::allocator_type exists and either is_convertible<Alloc, T::allocator_type>::value != false or T::allocator_type is an alias <code class="computeroutput"><a class="link" href="erased_type.html" title="Struct erased_type">erased_type</a></code>. False otherwise. </p> 42</div> 43</div> 44<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 45<td align="left"></td> 46<td align="right"><div class="copyright-footer">Copyright © 2009-2018 Ion Gaztanaga<p> 47 Distributed under the Boost Software License, Version 1.0. (See accompanying 48 file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) 49 </p> 50</div></td> 51</tr></table> 52<hr> 53<div class="spirit-nav"> 54<a accesskey="p" href="construc_idm45641208064992.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../boost_container_header_reference.html#header.boost.container.uses_allocator_hpp"><img src="../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="erased_type.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 55</div> 56</body> 57</html> 58
