// Boost.TypeErasure library
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//
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// Copyright 2011 Steven Watanabe
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//
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// Distributed under the Boost Software License Version 1.0. (See
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// accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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//
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// $Id$
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#ifndef BOOST_TYPE_ERASURE_DETAIL_IS_PLACEHOLDER_HPP_INCLUDED
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#define BOOST_TYPE_ERASURE_DETAIL_IS_PLACEHOLDER_HPP_INCLUDED
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#include <boost/mpl/bool.hpp>
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namespace boost {
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namespace type_erasure {
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#ifdef BOOST_TYPE_ERASURE_DOXYGEN
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/** A metafunction that indicates whether a type is a @ref placeholder. */
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template<class T>
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struct is_placeholder {};
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#else
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template<class T, class Enable = void>
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struct is_placeholder : ::boost::mpl::false_ {};
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template<class T>
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struct is_placeholder<T, typename T::_boost_type_erasure_is_placeholder> :
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::boost::mpl::true_ {};
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#endif
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}
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}
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#endif
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