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/*!
@file
Defines `boost::hana::detail::any_of`.
@copyright Louis Dionne 2013-2017
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_DETAIL_ANY_OF_HPP
#define BOOST_HANA_DETAIL_ANY_OF_HPP
#include <boost/hana/config.hpp>
#include <type_traits>
#include <utility>
BOOST_HANA_NAMESPACE_BEGIN namespace detail {
std::false_type expand(...);
template <template <typename ...> class Predicate, typename ...T>
decltype(expand(
typename std::enable_if<!Predicate<T>::value, void*>::type{}...
)) any_of_impl(int);
template <template <typename ...> class Predicate, typename ...T>
std::true_type any_of_impl(...);
//! @ingroup group-details
//! Returns whether the `Predicate` is satisfied by any of the `T...`.
//!
//! This metafunction will short-circuit the evaluation at the first
//! type satisfying the predicate, if such a type exists.
//!
//!
//! @note
//! The implementation technique used here was originally shown to
//! me by Eric Fiselier. All credits where due.
template <template <typename ...> class Predicate, typename ...T>
struct any_of
: decltype(any_of_impl<Predicate, T...>(int{}))
{ };
} BOOST_HANA_NAMESPACE_END
#endif // !BOOST_HANA_DETAIL_ANY_OF_HPP
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