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/*!
@file
Defines `boost::hana::Foldable`.
@copyright Louis Dionne 2013-2016
Distributed under the Boost Software License, Version 1.0.
(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
*/
#ifndef BOOST_HANA_CONCEPT_FOLDABLE_HPP
#define BOOST_HANA_CONCEPT_FOLDABLE_HPP
#include <boost/hana/fwd/concept/foldable.hpp>
#include <boost/hana/config.hpp>
#include <boost/hana/core/default.hpp>
#include <boost/hana/core/tag_of.hpp>
#include <boost/hana/detail/integral_constant.hpp>
#include <boost/hana/fold_left.hpp>
#include <boost/hana/unpack.hpp>
BOOST_HANA_NAMESPACE_BEGIN
template <typename T>
struct Foldable
: hana::integral_constant<bool,
!is_default<fold_left_impl<typename tag_of<T>::type>>::value ||
!is_default<unpack_impl<typename tag_of<T>::type>>::value
>
{ };
BOOST_HANA_NAMESPACE_END
#endif // !BOOST_HANA_CONCEPT_FOLDABLE_HPP
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