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| <div class="section"> |
| <div class="titlepage"><div><div><h4 class="title"> |
| <a name="fusion.sequence.operator.i_o"></a><a class="link" href="i_o.html" title="I/O">I/O</a> |
| </h4></div></div></div> |
| <div class="toc"><dl class="toc"> |
| <dt><span class="section"><a href="i_o/in.html">in</a></span></dt> |
| <dt><span class="section"><a href="i_o/out.html">out</a></span></dt> |
| </dl></div> |
| <p> |
| The I/O operators: <code class="computeroutput"><span class="special"><<</span></code> |
| and <code class="computeroutput"><span class="special">>></span></code> work generically |
| on all Fusion sequences. The I/O operators are overloaded in namespace |
| <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">fusion</span></code> <a href="#ftn.fusion.sequence.operator.i_o.f0" class="footnote" name="fusion.sequence.operator.i_o.f0"><sup class="footnote">[10]</sup></a> |
| </p> |
| <p> |
| The <code class="computeroutput"><span class="keyword">operator</span><span class="special"><<</span></code> |
| has been overloaded for generic output streams such that <a class="link" href="../../sequence.html" title="Sequence">Sequence</a>(s) |
| are output by recursively calling <code class="computeroutput"><span class="keyword">operator</span><span class="special"><<</span></code> for each element. Analogously, |
| the global <code class="computeroutput"><span class="keyword">operator</span><span class="special">>></span></code> |
| has been overloaded to extract <a class="link" href="../../sequence.html" title="Sequence">Sequence</a>(s) |
| from generic input streams by recursively calling <code class="computeroutput"><span class="keyword">operator</span><span class="special">>></span></code> for each element. |
| </p> |
| <p> |
| The default delimiter between the elements is space, and the <a class="link" href="../../sequence.html" title="Sequence">Sequence</a> |
| is enclosed in parenthesis. For Example: |
| </p> |
| <pre class="programlisting"><a class="link" href="../../container/vector.html" title="vector"><code class="computeroutput"><span class="identifier">vector</span></code></a><span class="special"><</span><span class="keyword">float</span><span class="special">,</span> <span class="keyword">int</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">></span> <span class="identifier">a</span><span class="special">(</span><span class="number">1.0f</span><span class="special">,</span> <span class="number">2</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="string">"Howdy folks!"</span><span class="special">);</span> |
| <span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">a</span><span class="special">;</span> |
| </pre> |
| <p> |
| outputs the <a class="link" href="../../container/vector.html" title="vector"><code class="computeroutput"><span class="identifier">vector</span></code></a> |
| as: (1.0 2 Howdy folks!) |
| </p> |
| <p> |
| The library defines three manipulators for changing the default behavior: |
| </p> |
| <div class="variablelist"> |
| <p class="title"><b>Manipulators</b></p> |
| <dl class="variablelist"> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">tuple_open</span><span class="special">(</span><span class="identifier">arg</span><span class="special">)</span></code></span></dt> |
| <dd><p> |
| Defines the character that is output before the first element. |
| </p></dd> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">tuple_close</span><span class="special">(</span><span class="identifier">arg</span><span class="special">)</span></code></span></dt> |
| <dd><p> |
| Defines the character that is output after the last element. |
| </p></dd> |
| <dt><span class="term"><code class="computeroutput"><span class="identifier">tuple_delimiter</span><span class="special">(</span><span class="identifier">arg</span><span class="special">)</span></code></span></dt> |
| <dd><p> |
| Defines the delimiter character between elements. |
| </p></dd> |
| </dl> |
| </div> |
| <p> |
| The argument to <code class="computeroutput"><span class="identifier">tuple_open</span></code>, |
| <code class="computeroutput"><span class="identifier">tuple_close</span></code> and <code class="computeroutput"><span class="identifier">tuple_delimiter</span></code> may be a <code class="computeroutput"><span class="keyword">char</span></code>, <code class="computeroutput"><span class="keyword">wchar_t</span></code>, |
| a C-string, or a wide C-string. |
| </p> |
| <p> |
| Example: |
| </p> |
| <pre class="programlisting"><span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">tuple_open</span><span class="special">(</span><span class="char">'['</span><span class="special">)</span> <span class="special"><<</span> <span class="identifier">tuple_close</span><span class="special">(</span><span class="char">']'</span><span class="special">)</span> <span class="special"><<</span> <span class="identifier">tuple_delimiter</span><span class="special">(</span><span class="string">", "</span><span class="special">)</span> <span class="special"><<</span> <span class="identifier">a</span><span class="special">;</span> |
| </pre> |
| <p> |
| outputs the same <a class="link" href="../../container/vector.html" title="vector"><code class="computeroutput"><span class="identifier">vector</span></code></a>, <code class="computeroutput"><span class="identifier">a</span></code> |
| as: [1.0, 2, Howdy folks!] |
| </p> |
| <p> |
| The same manipulators work with <code class="computeroutput"><span class="keyword">operator</span><span class="special">>></span></code> and <code class="computeroutput"><span class="identifier">istream</span></code> |
| as well. Suppose the <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">cin</span></code> |
| stream contains the following data: |
| </p> |
| <pre class="programlisting"><span class="special">(</span><span class="number">1</span> <span class="number">2</span> <span class="number">3</span><span class="special">)</span> <span class="special">[</span><span class="number">4</span><span class="special">:</span><span class="number">5</span><span class="special">]</span> |
| </pre> |
| <p> |
| The code: |
| </p> |
| <pre class="programlisting"><a class="link" href="../../container/vector.html" title="vector"><code class="computeroutput"><span class="identifier">vector</span></code></a><span class="special"><</span><span class="keyword">int</span><span class="special">,</span> <span class="keyword">int</span><span class="special">,</span> <span class="keyword">int</span><span class="special">></span> <span class="identifier">i</span><span class="special">;</span> |
| <a class="link" href="../../container/vector.html" title="vector"><code class="computeroutput"><span class="identifier">vector</span></code></a><span class="special"><</span><span class="keyword">int</span><span class="special">,</span> <span class="keyword">int</span><span class="special">></span> <span class="identifier">j</span><span class="special">;</span> |
| |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">cin</span> <span class="special">>></span> <span class="identifier">i</span><span class="special">;</span> |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">cin</span> <span class="special">>></span> <span class="identifier">tuple_open</span><span class="special">(</span><span class="char">'['</span><span class="special">)</span> <span class="special">>></span> <span class="identifier">tuple_close</span><span class="special">(</span><span class="char">']'</span><span class="special">)</span> <span class="special">>></span> <span class="identifier">tuple_delimiter</span><span class="special">(</span><span class="char">':'</span><span class="special">);</span> |
| <span class="identifier">std</span><span class="special">::</span><span class="identifier">cin</span> <span class="special">>></span> <span class="identifier">j</span><span class="special">;</span> |
| </pre> |
| <p> |
| reads the data into the <a class="link" href="../../container/vector.html" title="vector"><code class="computeroutput"><span class="identifier">vector</span></code></a>(s) <code class="computeroutput"><span class="identifier">i</span></code> |
| and <code class="computeroutput"><span class="identifier">j</span></code>. |
| </p> |
| <p> |
| Note that extracting <a class="link" href="../../sequence.html" title="Sequence">Sequence</a>(s) |
| with <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span></code> or C-style string elements does |
| not generally work, since the streamed <a class="link" href="../../sequence.html" title="Sequence">Sequence</a> |
| representation may not be unambiguously parseable. |
| </p> |
| <h6> |
| <a name="fusion.sequence.operator.i_o.h0"></a> |
| <span class="phrase"><a name="fusion.sequence.operator.i_o.header"></a></span><a class="link" href="i_o.html#fusion.sequence.operator.i_o.header">Header</a> |
| </h6> |
| <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fusion</span><span class="special">/</span><span class="identifier">sequence</span><span class="special">/</span><span class="identifier">io</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| <span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fusion</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">io</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> |
| </pre> |
| <div class="footnotes"> |
| <br><hr style="width:100; text-align:left;margin-left: 0"> |
| <div id="ftn.fusion.sequence.operator.i_o.f0" class="footnote"><p><a href="#fusion.sequence.operator.i_o.f0" class="para"><sup class="para">[10] </sup></a> |
| <a class="link" href="../../sequence.html" title="Sequence">Sequence</a>(s) and <a class="link" href="../../view.html" title="View">Views</a> |
| residing in different namespaces will have to either provide their own |
| I/O operators (possibly forwarding to fusion's I/O operators) or hoist |
| fusion's I/O operators (using declaration), in their own namespaces for |
| proper argument dependent lookup. |
| </p></div> |
| </div> |
| </div> |
| <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> |
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| <td align="right"><div class="copyright-footer">Copyright © 2001-2006, 2011, 2012 Joel de Guzman, |
| Dan Marsden, Tobias Schwinger<p> |
| 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" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) |
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