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15 <h1><a class=
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19 struct
<a href=
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"identifier">void_
</a>
21 typedef
<a href=
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"identifier">void_
</a> type;
24 template
< typename T
> struct is_void;
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29 <p><tt class=
"literal"><span class=
"pre"><a href=
"./void.html" class=
"identifier">void_
</a></span></tt> is a generic type placeholder representing
"nothing
".
</p>
30 <!-- In many cases, returning ``void_`` from a metafunction to signal
31 an absence of the requested data leads to a simpler user code than
32 having a separate metafunction specifically for the purpose of
33 performing the corresponding check. -->
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37 <pre class=
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38 #include
<<a href=
"../../../../boost/mpl/void.hpp" class=
"header">boost/mpl/void.hpp
</a>>
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49 <td><div class=
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2001-
2009 Aleksey Gurtovoy and David Abrahams
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50 Distributed under the Boost Software License, Version
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