//-----------------------------------------------------------------------------
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// boost variant/detail/has_result_type.hpp header file
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// See http://www.boost.org for updates, documentation, and revision history.
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//-----------------------------------------------------------------------------
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//
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// Copyright (c) 2014-2020 Antony Polukhin
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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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#ifndef BOOST_VARIANT_DETAIL_HAS_RESULT_TYPE_HPP
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#define BOOST_VARIANT_DETAIL_HAS_RESULT_TYPE_HPP
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#include <boost/config.hpp>
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#include <boost/type_traits/remove_reference.hpp>
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namespace boost { namespace detail { namespace variant {
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template <typename T >
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struct has_result_type {
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private:
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typedef char yes;
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typedef struct { char array[2]; } no;
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template<typename C> static yes test(typename boost::remove_reference<typename C::result_type>::type*);
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template<typename C> static no test(...);
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public:
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BOOST_STATIC_CONSTANT(bool, value = sizeof(test<T>(0)) == sizeof(yes));
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};
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}}} // namespace boost::detail::variant
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#endif // BOOST_VARIANT_DETAIL_HAS_RESULT_TYPE_HPP
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