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29 <pre class=
"programlisting"><span class=
"preprocessor">#include
</span> <span class=
"special"><</span><span class=
"identifier">boost
</span><span class=
"special">/
</span><span class=
"identifier">phoenix
</span><span class=
"special">/
</span><span class=
"identifier">core
</span><span class=
"special">/
</span><span class=
"identifier">nothing
</span><span class=
"special">.
</span><span class=
"identifier">hpp
</span><span class=
"special">></span>
32 Finally, the
<code class=
"computeroutput"><span class=
"identifier">expression
</span><span class=
"special">::
</span><span class=
"identifier">null
</span><span class=
"special"><</span><span class=
"identifier">mpl
</span><span class=
"special">::
</span><span class=
"identifier">void_
</span><span class=
"special">>::
</span><span class=
"identifier">type
</span></code>
33 does nothing; (a
"bum", if you will :-) ). There's a sole
<code class=
"computeroutput"><span class=
"identifier">expression
</span><span class=
"special">::
</span><span class=
"identifier">null
</span><span class=
"special"><</span><span class=
"identifier">mpl
</span><span class=
"special">::
</span><span class=
"identifier">void_
</span><span class=
"special">>::
</span><span class=
"identifier">type
</span></code> instance named
"nothing".
34 This actor is actually useful in situations where we don't want to do anything.
35 (See
<a class=
"link" href=
"../statement/for_statement.html" title=
"for_ Statement">for_ Statement
</a>
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© 2002-
2005,
2010,
2014,
2015 Joel de Guzman, Dan Marsden, Thomas
42 Heller, John Fletcher
<p>
43 Distributed under the Boost Software License, Version
1.0. (See accompanying
44 file LICENSE_1_0.txt or copy at
<a href=
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