1<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> 2<HTML> 3<HEAD> 4 <TITLE>The Boost Iostreams library</TITLE> 5 <LINK REL="stylesheet" HREF="../../../boost.css" type="text/css"> 6 <LINK REL="stylesheet" HREF="theme/iostreams.css" type="text/css"> 7</HEAD> 8<BODY> 9 10<!-- Begin Banner --> 11 12 <H1 CLASS="title">The Boost Iostreams Library</H1> 13 <HR CLASS="banner"> 14 15<!-- End Banner --> 16 17<DL CLASS="page-index"> 18 <DT><A href="#purpose">Purpose</A></DT> 19 <DT><A href="#overview">Overview</A></DT> 20 <DT><A href="#documentation">How to Read the Iostreams Documentation</A></DT> 21 <DT><A href="#conventions">Conventions</A></DT> 22</DL> 23 24<HR> 25 26<!-- Core Components --> 27 28<A NAME="purpose"></A> 29<H2>Purpose</H2> 30 31<P> 32 Boost.Iostreams has three aims: 33</P> 34<UL> 35 <LI CLASS="square"> 36 To make it easy to create standard C++ streams and stream buffers for accessing new <A HREF="concepts/source.html">Sources</A> and <A HREF="concepts/sink.html">Sinks</A>. 37 </LI> 38 <LI CLASS="square"> 39 To provide a framework for defining <A HREF="concepts/filter.html">Filters</A> and attaching them to standard streams and stream buffers. 40 </LI> 41 <LI CLASS="square"> 42 To provide a collection of ready-to-use Filters, Sources and Sinks. 43 </LI> 44</UL> 45 46<P> 47 For example, Boost.Iostreams can be used to create streams to access TCP connections or as a framework for cryptography and data compression. The library includes components for accessing <A HREF="classes/mapped_file.html">memory-mapped files</A>, for file access using operating system <A HREF="classes/file_descriptor.html">file descriptors</A>, for <A HREF="guide/code_conversion.html">code conversion</A>, for text filtering with <A HREF="classes/regex_filter.html">regular expressions</A>, for <A HREF="classes/newline_filter.html">line-ending conversion</A> and for compression and decompression in the <A HREF="classes/zlib.html">zlib</A>, <A HREF="classes/gzip.html">gzip</A> and <A HREF="classes/bzip2.html">bzip2</A> formats. 48</P> 49 50<A NAME="overview"></A> 51<H2>Overview</H2> 52 53<P> 54 At the heart of Boost.Iostreams are a collection of <A HREF="http://www.boost.org/more/generic_programming.html#concept" TARGET="_top">concepts</A> and set of templates which turn models of these concepts into C++ standard library streams and stream buffers. 55</P> 56 57<H3>Concepts</H3> 58 59<P> 60 The fundamental building blocks of the library are the concepts of a <A HREF="concepts/source.html">Source</A>, which provides read access to a sequence of characters, a <A HREF="concepts/sink.html">Sink</A>, which provides write access to a sequence of characters, an <A HREF="concepts/input_filter.html">InputFilter</A>, which filters input read from a Source, and an <A HREF="concepts/output_filter.html">OutputFilter</A>, which filters output written to a Sink. Sources, Sinks and their refinements are called <A HREF="concepts/device.html">Devices</A>. InputFilters, OutputFilters and their refinements are called <A HREF="concepts/filter.html">Filters</A>. 61</P> 62 63<H3>Generic Streams and Stream Buffers</H3> 64 65<P> 66 The class templates <A HREF="guide/generic_streams.html#stream_buffer"><CODE>stream_buffer</CODE></A> and <A HREF="guide/generic_streams.html#stream"><CODE>stream</CODE></A> implement standard stream buffers and streams which perform i/o by delegating to a contained <A HREF="concepts/device.html">Device</A>. The Device is accessed using member functions <CODE>open</CODE>, <CODE>is_open</CODE> and <CODE>close</CODE>, providing an interface similar to the standard file-based streams and stream buffers. 67</P> 68 69<H3>Filtering Streams and Stream Buffers</H3> 70 71<P> 72 For filtering, Boost.Iostreams provides the templates <A HREF="classes/filtering_streambuf.html"><CODE>filtering_streambuf</CODE></A> and <A HREF="classes/filtering_stream.html"><CODE>filtering_stream</CODE></A>. Instances of <CODE>filtering_streambuf</CODE> or <CODE>filtering_stream</CODE> contain <A HREF="classes/chain.html"><CODE>chains</CODE></A> of Filters and Devices accessed with an interface similar to that of <CODE>std::stack</CODE>. 73</P> 74 75<A NAME="documentation"></A> 76<H2>How to Read the Iostreams Documentation</H2> 77 78<P> 79 If you haven't used a pre-release version of the library, start by reading the <A HREF="tutorial/tutorial.html">Tutorial</A>. Read the entire section on writing <A HREF="concepts/device.html">Devices</A>, and at least the first few sections on writing <A HREF="concepts/filter.html">Filters</A>. Even if you've used the library before, you might want to check out the Tutorial, since the library interface has been modified to accommodate <A HREF="guide/asynchronous.html">Asynchronous and Non-Blocking I/O</A>. 80</P> 81 82<P> 83 Next, take a glance at the <A HREF="quick_reference.html">Quick Reference</A> to get an overview of Boost.Iostream's major components. 84</P> 85 86<P> 87 Finally, consult the <A HREF="guide/guide.html">User's Guide</A>, the <A HREF="reference.html">Reference</A> and the <A HREF="faq.html">FAQ</A> when you have questions not answered by the other sections. The <A HREF="guide/guide.html">User's Guide</A> consists of a collection of short essays, which are mostly independent of each other. The <A HREF="reference.html">Reference</A> contains detailed documentation of each public component of Boost.Iostreams. 88</P> 89 90<A NAME="conventions"></A> 91<H2>Conventions</H2> 92 93<P> 94 All classes, functions and templates introduced in the documentation are in the 95 namespace <CODE>boost::iostreams</CODE>, unless otherwise indicated. Namespace qualification is usually omitted. 96</P> 97<P> 98 Specializations of <CODE>std::basic_istream</CODE> will be referred to as 99 <SPAN CLASS="term">standard input streams</SPAN>, specializations of <CODE>std::basic_ostream</CODE> 100 as <SPAN CLASS="term">standard output streams</SPAN>, specializations of <CODE>std::basic_iostream</CODE> 101 as <SPAN CLASS="term">standard i/o streams</SPAN>, and specializations of <CODE>std::basic_streambuf</CODE> 102 as <SPAN CLASS="term">standard stream buffers</SPAN>. Together, standard input streams, standard output streams and standard i/o streams will be referred to as <SPAN CLASS="term">standard streams</SPAN>. Sometimes the qualifier <I>standard</I> will be omitted. 103</P> 104 105<!-- <UL> 106 <LI CLASS="square"> 107 All classes, functions and templates introduced in the documentation are in the namespace <CODE>boost::iostreams</CODE> unless otherwise indicated. Namespace qualification will usually be omitted. 108 </LI> 109 <LI CLASS="square"> 110 Specializations of <CODE>std::basic_istream</CODE> will be referred to as 111 <SPAN CLASS="term">standard input streams</SPAN>, specializations of <CODE>std::basic_ostream</CODE> 112 as <SPAN CLASS="term">standard output streams</SPAN>, specializations of <CODE>std::basic_iostream</CODE> 113 as <SPAN CLASS="term">standard i/o streams</SPAN>, and specializations of <CODE>std::basic_streambuf</CODE> 114 as <SPAN CLASS="term">standard stream buffers</SPAN>. Together, standard input streams, standard output streams and standard i/o streams will be referred to as <SPAN CLASS="term">standard streams</SPAN>. The qualifier <I>standard</I> will usually be omitted. 115 </LI> 116</UL> --> 117 118<!-- Begin Footer --> 119 120<HR> 121 122 123<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> 124<P CLASS="copyright"> 125 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>) 126</P> 127<!-- End Footer --> 128 129</BODY> 130