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< title > Macro BOOST_TTI_HAS_MEMBER_DATA< / title >
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< h2 > < span class = "refentrytitle" > Macro BOOST_TTI_HAS_MEMBER_DATA< / span > < / h2 >
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< p > BOOST_TTI_HAS_MEMBER_DATA — A macro which expands to a metafunction which tests whether a member data with a particular name and type exists. < / p >
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< h2 xmlns:rev = "http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class = "refsynopsisdiv-title" > Synopsis< / h2 >
< div xmlns:rev = "http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class = "refsynopsisdiv" > < pre class = "synopsis" > < span class = "comment" > // In header: < < a class = "link" href = "header/boost/tti/has_member_data_hpp.html" title = "Header <boost/tti/has_member_data.hpp>" > boost/tti/has_member_data.hpp< / a > >
< / span > BOOST_TTI_HAS_MEMBER_DATA(name)< / pre > < / div >
< div class = "refsect1" >
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< a name = "idm46191514032272" > < / a > < h2 > Description< / h2 >
< p > BOOST_TTI_HAS_MEMBER_DATA is a macro which expands to a metafunction. The metafunction tests whether member data with a particular name and type exists. The macro takes the form of BOOST_TTI_HAS_MEMBER_DATA(name) where< / p >
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< p > name = the name of the inner member.< / p >
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< p > BOOST_TTI_HAS_MEMBER_DATA generates a metafunction called "has_member_data_name" where 'name' is the macro parameter.< / p >
< pre class = "programlisting" > < span class = "keyword" > template< / span > < span class = "special" > < < / span > < span class = "keyword" > class< / span > < span class = "identifier" > BOOST_TTI_TP_ET< / span > < span class = "special" > ,< / span > < span class = "keyword" > class< / span > < span class = "identifier" > BOOST_TTI_TP_TYPE< / span > < span class = "special" > > < / span >
< span class = "keyword" > struct< / span > < span class = "identifier" > has_member_data_< / span > < span class = "char" > 'name'< / span >
< span class = "special" > {< / span >
< span class = "keyword" > static< / span > < span class = "keyword" > const< / span > < span class = "identifier" > value< / span > < span class = "special" > =< / span > < span class = "identifier" > unspecified< / span > < span class = "special" > ;< / span >
< span class = "keyword" > typedef< / span > < span class = "identifier" > mpl< / span > < span class = "special" > ::< / span > < span class = "identifier" > bool_< / span > < span class = "special" > < < / span > < span class = "keyword" > true< / span > < span class = "special" > -< / span > < span class = "identifier" > or< / span > < span class = "special" > -< / span > < span class = "keyword" > false< / span > < span class = "special" > > < / span > < span class = "identifier" > type< / span > < span class = "special" > ;< / span >
< span class = "special" > }< / span > < span class = "special" > ;< / span >
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< span class = "identifier" > The< / span > < span class = "identifier" > metafunction< / span > < span class = "identifier" > types< / span > < span class = "identifier" > and< / span > < span class = "keyword" > return< / span > < span class = "special" > :< / span >
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< span class = "identifier" > BOOST_TTI_TP_ET< / span > < span class = "special" > =< / span > < span class = "identifier" > the< / span > < span class = "identifier" > enclosing< / span > < span class = "identifier" > type< / span > < span class = "identifier" > in< / span > < span class = "identifier" > which< / span > < span class = "identifier" > to< / span > < span class = "identifier" > look< / span > < span class = "keyword" > for< / span > < span class = "identifier" > our< / span > < span class = "char" > 'name'< / span > < span class = "special" > .< / span >
< span class = "identifier" > The< / span > < span class = "identifier" > enclosing< / span > < span class = "identifier" > type< / span > < span class = "identifier" > can< / span > < span class = "identifier" > be< / span > < span class = "identifier" > a< / span > < span class = "keyword" > class< / span > < span class = "special" > ,< / span > < span class = "keyword" > struct< / span > < span class = "special" > ,< / span > < span class = "identifier" > or< / span > < span class = "keyword" > union< / span > < span class = "special" > .< / span >
< span class = "identifier" > OR< / span >
< span class = "identifier" > The< / span > < span class = "identifier" > type< / span > < span class = "identifier" > of< / span > < span class = "identifier" > the< / span > < span class = "identifier" > member< / span > < span class = "identifier" > data< / span > < span class = "identifier" > in< / span > < span class = "identifier" > the< / span > < span class = "identifier" > form< / span > < span class = "identifier" > of< / span > < span class = "identifier" > a< / span > < span class = "identifier" > pointer< / span >
< span class = "identifier" > to< / span > < span class = "identifier" > member< / span > < span class = "identifier" > data< / span > < span class = "special" > .< / span >
< span class = "identifier" > BOOST_TTI_TP_TYPE< / span > < span class = "special" > =< / span > < span class = "special" > (< / span > < span class = "identifier" > optional< / span > < span class = "special" > )< / span > < span class = "identifier" > The< / span > < span class = "identifier" > type< / span > < span class = "identifier" > of< / span > < span class = "identifier" > the< / span > < span class = "identifier" > member< / span > < span class = "identifier" > data< / span > < span class = "keyword" > if< / span > < span class = "identifier" > the< / span > < span class = "identifier" > first< / span >
< span class = "identifier" > parameter< / span > < span class = "identifier" > is< / span > < span class = "identifier" > the< / span > < span class = "identifier" > enclosing< / span > < span class = "identifier" > type< / span > < span class = "special" > .< / span >
< span class = "identifier" > returns< / span > < span class = "special" > =< / span > < span class = "char" > 'value'< / span > < span class = "identifier" > is< / span > < span class = "keyword" > true< / span > < span class = "keyword" > if< / span > < span class = "identifier" > the< / span > < span class = "char" > 'name'< / span > < span class = "identifier" > exists< / span > < span class = "special" > ,< / span > < span class = "identifier" > with< / span > < span class = "identifier" > the< / span > < span class = "identifier" > correct< / span > < span class = "identifier" > data< / span > < span class = "identifier" > type< / span > < span class = "special" > ,< / span >
< span class = "identifier" > otherwise< / span > < span class = "char" > 'value'< / span > < span class = "identifier" > is< / span > < span class = "keyword" > false< / span > < span class = "special" > .< / span >
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< p > < / p >
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< td align = "right" > < div class = "copyright-footer" > Copyright © 2011-2013 Tropic Software
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East Inc< 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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