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| <H1 CLASS="title">Function Template <CODE>optimal_buffer_size</CODE></H1> |
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| <DT><A href="#overview">Overview</A></DT> |
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| <H2>Overview</H2> |
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| The function template <CODE>optimal_buffer_size</CODE> returns the size of the character buffer which is allocated for a Filter or Device by library streams, stream buffers and chains if no buffer size is explicitly specified. |
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| <DT><A CLASS="header" HREF="../../../../boost/iostreams/optimal_buffer_size.hpp"><CODE><boost/iostreams/optimal_buffer_size.hpp></CODE></A></DT> |
| <DT><A CLASS="header" HREF="../../../../boost/iostreams/operations.hpp"><CODE><boost/iostreams/operations.hpp></CODE></A></DT> |
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| <H4>Synopsis</H4> |
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| <PRE CLASS="broken_ie"><SPAN CLASS="keyword">namespace</SPAN> boost { <SPAN CLASS="keyword">namespace</SPAN> iostreams { |
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| <SPAN CLASS="keyword">template</SPAN><<SPAN CLASS="keyword">typename</SPAN> <A CLASS="documented" HREF="#template_params">T</A>> |
| std::streamsize <A CLASS="documented" HREF="#optimal_buffer_size">optimal_buffer_size</A>(T& t); |
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| } } <SPAN CLASS="comment">// End namespace boost::io</SPAN></PRE> |
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| <H4>Template Parameters</H4> |
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| <TD VALIGN="top"><I>T</I></TD><TD WIDTH="2em" VALIGN="top">-</TD> |
| <TD>A model of <A HREF="../concepts/filter.html">Filter</A> or <A HREF="../concepts/device.html">Device</A>. |
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| <A NAME="optimal_buffer_size"></A> |
| <PRE CLASS="broken_ie"><SPAN CLASS="keyword">template</SPAN><<SPAN CLASS="keyword">typename</SPAN> T> |
| std::streamsize optimal_buffer_size(T& t);</PRE> |
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| <P>The semantics of <CODE>optimal_buffer_size</CODE> depends on the <A HREF="../guide/traits.html#category">category</A> of <CODE>T</CODE> as follows:</P> |
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| <TR><TH><CODE>category_of<T>::type</CODE></TH><TH>semantics</TH></TR> |
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| <TD VALIGN="top">convertible to <A HREF="../guide/traits.html#category_tags"><CODE>optimally_buffered_tag</CODE></A></TD> |
| <TD>Returns <CODE>t.optimal_buffer_size()</CODE>.</TD> |
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| <TD VALIGN="top">convertible to <A HREF="../guide/traits.html#category_tags"><CODE>filter_tag</CODE></A> but not to <A HREF="../guide/traits.html#category_tags"><CODE>optimally_buffered_tag</CODE></A></TD> |
| <TD>Returns <A HREF='../macros/buffer_sizes.html'><CODE>default_filter_buffer_size</CODE></A>.</TD> |
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| <TD VALIGN="top">otherwise</TD> |
| <TD>Returns <A HREF='../macros/buffer_sizes.html'><CODE>default_device_buffer_size</CODE></A>.</TD> |
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| <P CLASS="copyright">Revised 02 Feb 2008</P> |
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| <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> |
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| 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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