<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> <HTML> <HEAD> <TITLE>class template back_insert_device</TITLE> <LINK REL="stylesheet" HREF="../../../../boost.css"> <LINK REL="stylesheet" HREF="../theme/iostreams.css"> </HEAD> <BODY> <!-- Begin Banner --> <H1 CLASS="title">Class Template <CODE>back_insert_device</CODE></H1> <HR CLASS="banner"> <!-- End Banner --> <DL class="page-index"> <DT><A href="#description">Description</A></DT> <DT><A href="#headers">Headers</A></DT> <DT><A href="#synopsis">Synopsis</A></DT> </DL> <A NAME="description"></A> <H2>Description</H2> <P> 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>. </P> <P> 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 </P> <PRE CLASS="broken_ie"><SPAN CLASS="keyword">namespace</SPAN> io = boost::iostreams; <SPAN CLASS="keyword">typedef</SPAN> io::stream< io::back_insert_device<std::string> > my_stream</PRE> <P>But not</P> <PRE CLASS="broken_ie"><SPAN CLASS="keyword">typedef</SPAN> io::stream< std::back_insert_iterator<std::string> > my_stream</PRE> <A NAME="headers"></A> <H2>Headers</H2> <DL> <DT><A CLASS="header" HREF="../../../../boost/iostreams/device/back_inserter.hpp"><CODE><boost/iostreams/device/back_inserter.hpp></CODE></A></DT> </DL> <A NAME="synopsis"></A> <H2>Synopsis</H2> <PRE CLASS="broken_ie"><SPAN CLASS="keyword">namespace</SPAN> boost { <SPAN CLASS="keyword">namespace</SPAN> iostreams { <SPAN CLASS="keyword">template</SPAN><<SPAN CLASS="keyword">typename</SPAN> <A HREF="#back_insert_device_template_params" CLASS="documented">Container</A>> <SPAN CLASS="keyword">class</SPAN> <A HREF="#back_insert_device_template_params" CLASS="documented">back_insert_device</A> { <SPAN CLASS="keyword">public</SPAN>: <SPAN CLASS="keyword">typedef</SPAN> <SPAN CLASS="keyword">typename</SPAN> Container::value_type char_type; <SPAN CLASS="keyword">typedef</SPAN> sink_tag category; <A HREF="#back_insert_device_constructor" CLASS="documented">back_insert_device</A>(Container& cnt); <SPAN CLASS="omitted">...</SPAN> }; <SPAN CLASS="keyword">template</SPAN><<SPAN CLASS="keyword">typename</SPAN> <A HREF="#back_insert_device_template_params" CLASS="documented">Container</A>> <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); } } <SPAN CLASS="comment">// End namespace boost::io</SPAN></PRE> <A NAME="back_insert_device_template_params"></A> <H4>Template Parameters</H4> <TABLE STYLE="margin-left:2em" BORDER=0 CELLPADDING=2> <TR> <TR> <TD VALIGN="top"><I>Container</I></TD><TD WIDTH="2em" VALIGN="top">-</TD> <TD>A C++ standard library sequence type (<A CLASS="bib_ref" HREF="../bibliography.html#iso">[ISO]</A>, 23.1.1). </TR> </TABLE> <A NAME="back_insert_device_constructor"></A> <H4><CODE>back_insert_device::back_insert_device</CODE></H4> <PRE CLASS="broken_ie"> back_insert_device(Container& cnt);</PRE> <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> <A NAME="back_inserter"></A> <H4><CODE>back_inserter</CODE></H4> <PRE CLASS="broken_ie"><SPAN CLASS="keyword">template</SPAN><<SPAN CLASS="keyword">typename</SPAN> Container> back_insert_device<Container> back_inserter(Container& cnt);</PRE> <P>Returns an instance of <CODE>back_insert_device</CODE> for appending to the given container.</P> <!-- Begin Footer --> <HR> <P CLASS="copyright">Revised 02 Feb 2008</P> <P CLASS="copyright">© Copyright 2008 <a href="http://www.coderage.com/" target="_top">CodeRage, LLC</a><br/>© Copyright 2004-2007 <a href="http://www.coderage.com/turkanis/" target="_top">Jonathan Turkanis</a></P> <P CLASS="copyright"> 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>) </P> <!-- End Footer --> </BODY>