1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2<HTML> 3<HEAD> 4 <TITLE>class template back_insert_device</TITLE> 5 <LINK REL="stylesheet" HREF="../../../../boost.css"> 6 <LINK REL="stylesheet" HREF="../theme/iostreams.css"> 7</HEAD> 8<BODY> 9 10<!-- Begin Banner --> 11 12 <H1 CLASS="title">Class Template <CODE>back_insert_device</CODE></H1> 13 <HR CLASS="banner"> 14 15<!-- End Banner --> 16 17<DL class="page-index"> 18 <DT><A href="#description">Description</A></DT> 19 <DT><A href="#headers">Headers</A></DT> 20 <DT><A href="#synopsis">Synopsis</A></DT> 21</DL> 22 23<A NAME="description"></A> 24<H2>Description</H2> 25 26<P> 27 The header <A CLASS="header" HREF="../../../../boost/iostreams/device/back_inserter.hpp"><CODE><boost/iostreams/device/back_inserter.hpp></CODE></A> contains the definition of the class template <CODE>back_insert_device</CODE> — implementing a <A HREF="../concepts/sink.html">Sink</A> which appends to a standard library sequence container — as well as the definition of a corresponding object generator, the function template <CODE>boost::iostreams::back_inserter</CODE>. 28</P> 29 30<P> 31 The Iostream Library allows OutputIterators to be used in many places where <A HREF="../concepts/sink.html">Sinks</A> are allowed. However, using <CODE>boost::iostreams::back_inserter</CODE> my be somewhat more efficient than using <CODE>std::back_inserter</CODE>, since the former uses the function <CODE>insert</CODE> to append a sequence of characters in one operation. Furthermore, <CODE>std::back_insert_iterator</CODE> is not strictly a model of <A HREF="../concepts/sink.html">Sink</A>, so one can write 32</P> 33 34<PRE CLASS="broken_ie"><SPAN CLASS="keyword">namespace</SPAN> io = boost::iostreams; 35 36<SPAN CLASS="keyword">typedef</SPAN> io::stream< io::back_insert_device<std::string> > my_stream</PRE> 37 38<P>But not</P> 39 40<PRE CLASS="broken_ie"><SPAN CLASS="keyword">typedef</SPAN> io::stream< std::back_insert_iterator<std::string> > my_stream</PRE> 41 42<A NAME="headers"></A> 43<H2>Headers</H2> 44 45<DL> 46 <DT><A CLASS="header" HREF="../../../../boost/iostreams/device/back_inserter.hpp"><CODE><boost/iostreams/device/back_inserter.hpp></CODE></A></DT> 47</DL> 48 49<A NAME="synopsis"></A> 50<H2>Synopsis</H2> 51 52<PRE CLASS="broken_ie"><SPAN CLASS="keyword">namespace</SPAN> boost { <SPAN CLASS="keyword">namespace</SPAN> iostreams { 53 54<SPAN CLASS="keyword">template</SPAN><<SPAN CLASS="keyword">typename</SPAN> <A HREF="#back_insert_device_template_params" CLASS="documented">Container</A>> 55<SPAN CLASS="keyword">class</SPAN> <A HREF="#back_insert_device_template_params" CLASS="documented">back_insert_device</A> { 56<SPAN CLASS="keyword">public</SPAN>: 57 <SPAN CLASS="keyword">typedef</SPAN> <SPAN CLASS="keyword">typename</SPAN> Container::value_type char_type; 58 <SPAN CLASS="keyword">typedef</SPAN> sink_tag category; 59 <A HREF="#back_insert_device_constructor" CLASS="documented">back_insert_device</A>(Container& cnt); 60 <SPAN CLASS="omitted">...</SPAN> 61}; 62 63<SPAN CLASS="keyword">template</SPAN><<SPAN CLASS="keyword">typename</SPAN> <A HREF="#back_insert_device_template_params" CLASS="documented">Container</A>> 64<A CLASS="documented" HREF="#back_insert_device_template_params">back_insert_device</A><Container> <A CLASS="documented" HREF="#back_inserter">back_inserter</A>(Container& cnt); 65 66} } <SPAN CLASS="comment">// End namespace boost::io</SPAN></PRE> 67 68<A NAME="back_insert_device_template_params"></A> 69<H4>Template Parameters</H4> 70 71<TABLE STYLE="margin-left:2em" BORDER=0 CELLPADDING=2> 72<TR> 73 <TR> 74 <TD VALIGN="top"><I>Container</I></TD><TD WIDTH="2em" VALIGN="top">-</TD> 75 <TD>A C++ standard library sequence type (<A CLASS="bib_ref" HREF="../bibliography.html#iso">[ISO]</A>, 23.1.1). 76 </TR> 77</TABLE> 78 79<A NAME="back_insert_device_constructor"></A> 80<H4><CODE>back_insert_device::back_insert_device</CODE></H4> 81 82<PRE CLASS="broken_ie"> back_insert_device(Container& cnt);</PRE> 83 84<P>Constructs an instance of <CODE>back_insert_device</CODE> for appending to the given container. The given reference must remain valid for the lifetime of the instance of <CODE>back_insert_device</CODE>.</P> 85 86<A NAME="back_inserter"></A> 87<H4><CODE>back_inserter</CODE></H4> 88 89<PRE CLASS="broken_ie"><SPAN CLASS="keyword">template</SPAN><<SPAN CLASS="keyword">typename</SPAN> Container> 90back_insert_device<Container> back_inserter(Container& cnt);</PRE> 91 92<P>Returns an instance of <CODE>back_insert_device</CODE> for appending to the given container.</P> 93 94<!-- Begin Footer --> 95 96<HR> 97 98<P CLASS="copyright">© Copyright 2008 <a href="http://www.coderage.com/" target="_top">CodeRage, LLC</a><br/>© Copyright 2004-2007 <a href="https://www.boost.org/users/people/jonathan_turkanis.html" target="_top">Jonathan Turkanis</a></P> 99<P CLASS="copyright"> 100 Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <A HREF="http://www.boost.org/LICENSE_1_0.txt">http://www.boost.org/LICENSE_1_0.txt</A>) 101</P> 102 103<!-- End Footer --> 104 105</BODY>