iostreams/doc/functions/put.html

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<H1 CLASS="title">Function Template <CODE>put</CODE></H1>
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<DT><A href="#overview">Overview</A></DT>
<DT><A href="#example">Example</A></DT>
<DT><A href="#headers">Headers</A></DT>
<DT><A href="#reference">Reference</A></DT>
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<A NAME="overview"></A>
<H2>Overview</H2>
<P>
The function template <CODE>put</CODE> provides a uniform interface for writing a character to a <A HREF="../concepts/sink.html">Sink</A>, for use in the definitions of new <A HREF="../guide/concepts.html#filter_concepts">Filter</A> types (<I>see</I> <A HREF="#example">Example</A>).
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<A NAME="example"></A>
<H2>Example</H2>
<P>
The following code illustrates the use of the function <CODE>put</CODE> in the definition of an <A HREF="../concepts/output_filter.html">OutputFilter</A>.
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<PRE CLASS="broken_ie"> <SPAN CLASS="preprocessor">#include</SPAN> <SPAN CLASS="literal">&lt;ctype.h&gt;</SPAN> <SPAN CLASS="comment">// toupper</SPAN>
<SPAN CLASS="preprocessor">#include</SPAN> <A CLASS="header" HREF="../../../../boost/iostreams/concepts.hpp"><SPAN CLASS="literal">&lt;boost/iostreams/concepts.hpp&gt;</SPAN></A> <SPAN CLASS="comment">// output_filter</SPAN>
<SPAN CLASS="preprocessor">#include</SPAN> <A CLASS="header" HREF="../../../../boost/iostreams/operations.hpp"><SPAN CLASS="literal">&lt;boost/iostreams/operations.hpp&gt;</SPAN></A> <SPAN CLASS="comment">// put</SPAN>
<SPAN CLASS="keyword">using</SPAN> <SPAN CLASS="keyword">namespace</SPAN> std;
<SPAN CLASS="keyword">namespace</SPAN> io = boost::iostreams;
<SPAN CLASS="keyword">struct</SPAN> toupper_filter : <SPAN CLASS="keyword">public</SPAN> io::output_filter {
<SPAN CLASS="keyword">template</SPAN>&lt;<SPAN CLASS="keyword">typename</SPAN> Sink&gt;
<SPAN CLASS="keyword">bool</SPAN> put(Sink&amp; snk, <SPAN CLASS="keyword">char</SPAN> c)
{
<SPAN CLASS="keyword">return</SPAN> io::put(snk, toupper((<SPAN CLASS="keyword">unsigned</SPAN> <SPAN CLASS="keyword">char</SPAN>) c));
}
};</PRE>
<A NAME="headers"></A>
<H2>Headers</H2>
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<DT><A CLASS="header" HREF="../../../../boost/iostreams/operations.hpp"><CODE>&lt;boost/iostreams/operations.hpp&gt;</CODE></A></DT>
<DT><A CLASS="header" HREF="../../../../boost/iostreams/put.hpp"><CODE>&lt;boost/iostreams/put.hpp&gt;</CODE></A></DT>
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<A NAME="reference"></A>
<H2>Reference</H2>
<A NAME="description"></A>
<H4>Description</H4>
<P>Attempts to write a character to a given instance of the template parameter <CODE>Sink</CODE>, returning <CODE>true</CODE> for success.</P>
<A NAME="synopsis"></A>
<H4>Synopsis</H4>
<PRE CLASS="broken_ie"><SPAN CLASS="keyword">namespace</SPAN> boost { <SPAN CLASS="keyword">namespace</SPAN> iostreams {
<SPAN CLASS="keyword">template</SPAN>&lt;<SPAN CLASS="keyword">typename</SPAN> <A CLASS="documented" HREF="#template_params">Sink</A>&gt;
<SPAN CLASS="keyword">void</SPAN> put(Sink&amp; <A CLASS="documented" HREF="#function_params">snk</A>, <SPAN CLASS="keyword">typename</SPAN> <A CLASS="documented" HREF="../guide/traits.html#char_type_of_ref">char_type_of</A>&lt;Sink&gt;::type c);
} } <SPAN CLASS="comment">// End namespace boost::io</SPAN></PRE>
<A NAME="template_params"></A>
<H4>Template Parameters</H4>
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<TD VALIGN="top"><I>Sink</I></TD><TD WIDTH="2em" VALIGN="top">-</TD>
<TD>A <A HREF="../concepts/direct.html">indirect</A> model of <A HREF="../concepts/sink.html">Sink</A> or a standard output stream or stream buffer type.
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<A NAME="function_params"></A>
<H4>Function Parameters</H4>
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<TD VALIGN="top"><I>snk</I></TD><TD WIDTH="2em" VALIGN="top">-</TD>
<TD>An instance of <CODE>Sink</CODE></TD>
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<A NAME="semantics"></A>
<H4>Semantics</H4>
<PRE CLASS="broken_ie"> <SPAN CLASS="keyword">template</SPAN>&lt;<SPAN CLASS="keyword">typename</SPAN> Sink&gt;
<SPAN CLASS="keyword">void</SPAN> put(Sink&amp; snk, <SPAN CLASS="keyword">typename</SPAN> char_type_of&lt;Sink&gt;::type c);</PRE>
<P>The semantics of <CODE>put</CODE> depends on the <A HREF="../guide/traits.html#category">category</A> of <CODE>Sink</CODE> as follows:</P>
<TABLE STYLE="margin:0,0,2em,2em" BORDER=1 CELLPADDING=4>
<TR><TH><CODE>category_of&lt;Sink&gt;::type</CODE></TH><TH>semantics</TH></TR>
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<TD VALIGN="top">convertible to <A HREF="../guide/traits.html#category_tags"><CODE>direct_tag</CODE></A></TD>
<TD>compile-time error</CODE></TD>
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<TD VALIGN="top">convertible to <A HREF="../guide/traits.html#category_tags"><CODE>ostream_tag</CODE></A></TD>
<TD>invokes <CODE>snk.put(c)</CODE></TD>
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<TD VALIGN="top">convertible to <A HREF="../guide/traits.html#category_tags"><CODE>streambuf_tag</CODE></A> but not to <A HREF="../guide/traits.html#category_tags"><CODE>ostream_tag</CODE></A></TD>
<TD>invokes <CODE>snk.sputc(c)</CODE></TD>
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<TD VALIGN="top">otherwise</TD>
<TD>invokes <CODE>snk.write(&amp;c, 1)</CODE></TD>
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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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