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< h1 > < a class = "toc-backref" href = "./data-types-miscellaneous.html#id1585" > void_< / a > < / h1 >
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struct < a href = "./void.html" class = "identifier" > void_< / a >
{
typedef < a href = "./void.html" class = "identifier" > void_< / a > type;
};
template< typename T > struct is_void;
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< h3 > < a class = "subsection-title" href = "#description" name = "description" > Description< / a > < / h3 >
< 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 >
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<!-- In many cases, returning ``void_`` from a metafunction to signal
an absence of the requested data leads to a simpler user code than
having a separate metafunction specifically for the purpose of
performing the corresponding check. -->
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#include < < a href = "../../../../boost/mpl/void.hpp" class = "header" > boost/mpl/void.hpp< / a > >
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< p > < a class = "reference internal" href = "./data-types.html" > Data Types< / a > , < a class = "reference internal" href = "./pair.html" > pair< / a > , < a class = "reference internal" href = "./empty-base.html" > empty_base< / a > , < a class = "reference internal" href = "./bool.html" > bool_< / a > , < a class = "reference internal" href = "./int.html" > int_< / a > , < a class = "reference internal" href = "./integral-c.html" > integral_c< / a > < / p >
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< td > < div class = "copyright-footer" > < div class = "copyright" > Copyright © 2001-2009 Aleksey Gurtovoy and David Abrahams< / div >
Distributed under the Boost Software License, Version 1.0. (See accompanying
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