ceph/src/boost/libs/iostreams/doc/functions/restrict.html

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   4     <TITLE>Function Template restrict</TITLE>
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  12     <H1 CLASS="title">Function Template <CODE>restrict</CODE></H1>
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  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="#reference">Reference</A></DT>
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  24
  25 <A NAME="description"></A>
  26 <H2>Description</H2>
  27
  28 <P>
  29     Given a Filter or Device that provides access to a single character sequence, we can construct a second Filter or Device which provides access to contiguous subsequence of the the original sequence. This second Filter or Device is called a <I>restriction</I> of the original device. Restrictions are represented by instances of the class template <CODE>restriction</CODE>. The function template <CODE>resrict</CODE> is an <A HREF='http://www.boost.org/more/generic_programming.html#object_generator' TARGET='_top'>object generator</A> which returns an appropriate instance of <CODE>resriction</CODE> when passed a Filter or Device and a pair of values indicating the endpoints of the restricted subsequence.
  30 </P>
  31
  32 <P>
  33     The <A HREF='../guide/modes.html'>mode</A> of a <CODE>resriction</CODE> is the same as that of the underlying component. A <CODE>resriction</CODE> is <A HREF='../concepts/closable.html'>Closable</A>, <A HREF='../concepts/flushable.html'>Flushable</A>, <A HREF='../concepts/localizable.html'>Localizable</A> and <A HREF='../concepts/optimally_buffered.html'>OptimallyBuffered</A>.
  34 </P>
  35
  36 <P>
  37     The function template <a href="slice.html"><code>slice</code></a> is available as an alias of <code>restrict</code>, for platforms that treat <code>restrict</code> as a keyword.
  38 </P>
  39
  40 <A NAME="headers"></A>
  41 <H2>Headers</H2>
  42
  43 <DL class="page-index">
  44   <DT><A CLASS="header" HREF="../../../../boost/iostreams/restrict.hpp"><CODE>&lt;boost/iostreams/restrict.hpp&gt;</CODE></A></DT>
  45 </DL>
  46
  47 <A NAME="reference"></A>
  48 <H2>Reference</H2>
  49
  50 <A NAME="synopsis"></A>
  51 <H4>Synopsis</H4>
  52
  53 <PRE CLASS="broken_ie"><SPAN CLASS="keyword">namespace</SPAN> boost { <SPAN CLASS="keyword">namespace</SPAN> iostreams {
  54
  55 <SPAN CLASS="keyword">template</SPAN>&lt;<SPAN CLASS="keyword">typename</SPAN> <A CLASS="documented" HREF="#restriction_template_params">Component</A>&gt;
  56 <SPAN CLASS='keyword'>class</SPAN> <A CLASS='documented' HREF='#restriction'>restriction</A> {
  57 <SPAN CLASS='keyword'>public:</SPAN>
  58     <SPAN CLASS='keyword'>typedef</SPAN> <SPAN CLASS='keyword'>typename</SPAN> <A CLASS='documented' HREF='../guide/traits.html#char_type_of_ref'>char_type_of</A>&lt;Component&gt;::type  char_type;
  59     <SPAN CLASS='keyword'>typedef</SPAN> <SPAN CLASS='omitted'>implementation-defined</SPAN>                  mode;
  60
  61     <A CLASS='documented' HREF='#restriction_ctor'>restriction</A>( [<SPAN CLASS='keyword'>const</SPAN>] Component&amp; component,
  62                  <A CLASS='documented' HREF='positioning.html#synopsis'>stream_offset</A> off,
  63                  <A CLASS='documented' HREF='positioning.html#synopsis'>stream_offset</A> len = <SPAN     CLASS='literal'>-1</SPAN> );
  64
  65     <SPAN CLASS='comment'>// Filter or Device member functions</SPAN>
  66 };
  67
  68 <SPAN CLASS="keyword">template</SPAN>&lt;<SPAN CLASS="keyword">typename</SPAN> <A CLASS="documented" HREF="#restrict_template_params">Component</A>&gt;
  69 <A CLASS='documented' HREF='#restriction'>restriction</A>&lt;Component&gt;
  70 <A CLASS='documented' HREF='#restrict'>restrict</A>( [<SPAN CLASS='keyword'>const</SPAN>] Component&amp; component,
  71           <A CLASS='documented' HREF='positioning.html#synopsis'>stream_offset</A> off,
  72           <A CLASS='documented' HREF='positioning.html#synopsis'>stream_offset</A> len = <SPAN     CLASS='literal'>-1</SPAN> );
  73
  74 } } // End namespace boost::io</PRE>
  75
  76 <A NAME="restriction"></A>
  77 <H2>Class Template <CODE>restriction</CODE></H2>
  78
  79 <A NAME="restriction_template_params"></A>
  80 <H4>Template parameters</H4>
  81
  82 <TABLE STYLE="margin-left:2em" BORDER=0 CELLPADDING=2>
  83 <TR>
  84     <TR>
  85         <TD VALIGN="top"><I>Component</I></TD><TD WIDTH="2em" VALIGN="top">-</TD>
  86         <TD>A model of <A HREF='../concepts/filter.html'>Filter</A> or <A HREF='../concepts/device.html'>Device</A></TD>
  87     </TR>
  88 </TABLE>
  89
  90 <A NAME="restriction_ctor"></A>
  91 <H4><CODE>restriction::restriction</CODE></H4>
  92
  93 <PRE CLASS="broken_ie">    restriction( [<SPAN CLASS='keyword'>const</SPAN>] Component&amp; component,
  94                  <A CLASS='documented' HREF='positioning.html#synopsis'>stream_offset</A> off,
  95                  <A CLASS='documented' HREF='positioning.html#synopsis'>stream_offset</A> len = <SPAN     CLASS='literal'>-1</SPAN> );</PRE>
  96
  97 <P>
  98     Constructs an instance of <CODE>restriction</CODE> based on the given component and offsets. The parameters have the following interpretation:
  99 </P>
 100
 101 <TABLE STYLE="margin-left:2em" BORDER=0 CELLPADDING=2>
 102 <TR>
 103     <TR>
 104         <TD VALIGN="top"><I>component</I></TD><TD WIDTH="2em" VALIGN="top">-</TD>
 105         <TD>The Filter or Device to be restricted. If <CODE>Component</CODE> is a stream or stream buffer type, the function parameter is a non-<CODE>const</CODE> reference; otherwise it is a <CODE>const</CODE> reference.</TD>
 106     </TR>
 107     <TR>
 108         <TD VALIGN="top"><I>off</I></TD><TD WIDTH="2em" VALIGN="top">-</TD>
 109         <TD>The offset of the beginning of the restricted character sequence.</TD>
 110     </TR>
 111     <TR>
 112         <TD VALIGN="top"><I>len</I></TD><TD WIDTH="2em" VALIGN="top">-</TD>
 113         <TD>The length of the restricted character sequence. A value of <CODE>-1</CODE> indicates that the end of the restricted sequence should be the same as that of the unrestricted sequence.</TD>
 114     </TR>
 115 </TABLE>
 116
 117 <A NAME="restrict"></A>
 118 <H2>Function Template <CODE>restrict</CODE></H2>
 119
 120 <PRE CLASS="broken_ie"><SPAN CLASS="keyword">template</SPAN>&lt;<SPAN CLASS="keyword">typename</SPAN> Component&gt;
 121 restriction&lt;Component&gt;
 122 restrict( [<SPAN CLASS='keyword'>const</SPAN>] Component&amp; component,
 123           <A CLASS='documented' HREF='positioning.html#synopsis'>stream_offset</A> off,
 124           <A CLASS='documented' HREF='positioning.html#synopsis'>stream_offset</A> len = <SPAN     CLASS='literal'>-1</SPAN> );</PRE>
 125
 126 <A NAME="restrict_template_params"></A>
 127 <H4>Template parameters</H4>
 128
 129 <TABLE STYLE="margin-left:2em" BORDER=0 CELLPADDING=2>
 130 <TR>
 131     <TR>
 132         <TD VALIGN="top"><I>Component</I></TD><TD WIDTH="2em" VALIGN="top">-</TD>
 133         <TD>A model of <A HREF='../concepts/filter.html'>Filter</A> or <A HREF='../concepts/device.html'>Device</A></TD>
 134     </TR>
 135 </TABLE>
 136
 137 <P>
 138     Constructs an instance of an appropriate specialization of <CODE>restriction</CODE> based on the given component and offsets. The parameters have the following interpretation:
 139 </P>
 140
 141 <TABLE STYLE="margin-left:2em" BORDER=0 CELLPADDING=2>
 142 <TR>
 143     <TR>
 144         <TD VALIGN="top"><I>component</I></TD><TD WIDTH="2em" VALIGN="top">-</TD>
 145         <TD>The Filter or Device to be restricted. If <CODE>Component</CODE> is a stream or stream buffer type, the function parameter is a non-<CODE>const</CODE> reference; otherwise it is a <CODE>const</CODE> reference.</TD>
 146     </TR>
 147     <TR>
 148         <TD VALIGN="top"><I>off</I></TD><TD WIDTH="2em" VALIGN="top">-</TD>
 149         <TD>The offset of the beginning of the restricted character sequence.</TD>
 150     </TR>
 151     <TR>
 152         <TD VALIGN="top"><I>len</I></TD><TD WIDTH="2em" VALIGN="top">-</TD>
 153         <TD>The length of the restricted character sequence. A value of <CODE>-1</CODE> indicates that the end of the restricted sequence should be the same as that of the unrestricted sequence.</TD>
 154     </TR>
 155 </TABLE>
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 163     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>)
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