mirror of
https://github.com/boostorg/iostreams.git
synced 2026-02-22 03:22:24 +00:00
98 lines
4.3 KiB
HTML
Executable File
98 lines
4.3 KiB
HTML
Executable File
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
|
|
<HTML>
|
|
<HEAD>
|
|
<TITLE>Function Template reverse</TITLE>
|
|
<LINK REL="stylesheet" HREF="../../../../boost.css">
|
|
<LINK REL="stylesheet" HREF="../theme/iostreams.css">
|
|
</HEAD>
|
|
<BODY>
|
|
|
|
<!-- Begin Banner -->
|
|
|
|
<H1 CLASS="title">Function Template <CODE>reverse</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>
|
|
<DT><A href="#synopsis">Example</A></DT>
|
|
</DL>
|
|
|
|
<A NAME="description">
|
|
<H2>Description</H2>
|
|
|
|
<P>
|
|
The function template <CODE>reverse</CODE> takes a Filter and returns a new Filter which performs the same filtering operation as the original Filter but which is an <A HREF="../concepts/output_filter.html">OutputFilter</A> if the orginal Filter was an <A HREF="../concepts/input_filter.html">InputFilter</A> and and <A HREF="../concepts/input_filter.html">InputFilter</A> if the orginal Filter was an <A HREF="../concepts/output_filter.html">OutputFilter</A>. Roughly speaking, it <I>reverses</I> the direction of a given Filter.
|
|
</P>
|
|
|
|
<P>
|
|
The implementation of <CODE>reverse</CODE> makes use of the class template <A HREF="../classes/one_step_filter.html"><CODE>one_step_filter</CODE></A>, which filters an entire sequence of data at once. Therefore, a Filter returned by <CODE>reverse</CODE> may have higher memory use than the original Filter and is unsuitable for use with streams of data which have no definite endpoint.
|
|
</P>
|
|
|
|
<A NAME="headers">
|
|
<H2>Headers</H2>
|
|
|
|
<DL>
|
|
<DT><A CLASS="header" HREF="../../../../boost/iostreams/reverse.hpp"><CODE><boost/iostreams/reverse.hpp></CODE></A></DT>
|
|
</DL>
|
|
|
|
<A NAME="synopsis">
|
|
<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> Filter>
|
|
<SPAN CLASS="omitted">implementation-defined</SPAN> <SPAN CLASS="defined">reverse</SPAN>(<SPAN CLASS="keyword">const</SPAN> Filter& filter);
|
|
|
|
} } <SPAN CLASS="comment">// End namespace boost::io</SPAN></PRE>
|
|
|
|
<A NAME="example">
|
|
<H2>Example</H2>
|
|
|
|
The following example defines an <A HREF="../concepts/output_filter.html">OutputFilter</A> and uses it to filter standard input.
|
|
|
|
<PRE CLASS="broken_ie"><SPAN CLASS="preprocessor">#include</SPAN> <SPAN CLASS="literal"><cctype></SPAN> <SPAN CLASS="comment">// toupper</SPAN>
|
|
<SPAN CLASS="preprocessor">#include</SPAN> <SPAN CLASS="literal"><iostream></SPAN>
|
|
<SPAN CLASS="preprocessor">#include</SPAN> <A CLASS="header" HREF="../../../../boost/iostreams/concepts.hpp"><SPAN CLASS="literal"><boost/iostreams/concepts.hpp></SPAN></A> <SPAN CLASS="comment">// output_filter</SPAN>
|
|
<SPAN CLASS="preprocessor">#include</SPAN> <A CLASS="header" HREF="../../../../boost/iostreams/filtering_stream.hpp"><SPAN CLASS="literal"><boost/iostreams/filtering_stream.hpp></SPAN></A>
|
|
<SPAN CLASS="preprocessor">#include</SPAN> <A CLASS="header" HREF="../../../../boost/iostreams/reverse.hpp"><SPAN CLASS="literal"><boost/iostreams/reverse.hpp></SPAN></A>
|
|
|
|
<SPAN CLASS="keyword">using</SPAN> <SPAN CLASS="keyword">namespace</SPAN> std;
|
|
<SPAN CLASS="keyword">using</SPAN> <SPAN CLASS="keyword">namespace</SPAN> boost::io;
|
|
|
|
<SPAN CLASS="comment">// Converts characters to uppercase</SPAN>
|
|
<SPAN CLASS="keyword">struct</SPAN> toupper_filter : output_filter {
|
|
<SPAN CLASS="keyword">void</SPAN> put(<SPAN CLASS="keyword">char</SPAN> c, std::streambuf& dest)
|
|
{
|
|
dest.sputc(toupper(c));
|
|
}
|
|
};
|
|
|
|
<SPAN CLASS="keyword">int</SPAN> main()
|
|
{
|
|
filtering_stream<input> in;
|
|
in.push(reverse(toupper_filter()));
|
|
in.push(cin);
|
|
<SPAN CLASS="omitted">...</SPAN>
|
|
}</PRE>
|
|
|
|
<!-- Begin Footer -->
|
|
|
|
<HR>
|
|
<P CLASS="copyright">Revised
|
|
<!--webbot bot="Timestamp" S-Type="EDITED" S-Format="%d %B, %Y" startspan -->
|
|
20 May, 2004
|
|
<!--webbot bot="Timestamp" endspan i-checksum="38504" -->
|
|
</P>
|
|
|
|
<P CLASS="copyright">© Copyright Jonathan Turkanis, 2004</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> |