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- // 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)
- #include <boost/hana/optional.hpp>
- #include <boost/hana/type.hpp>
- #include <type_traits>
- namespace hana = boost::hana;
- // This test makes sure that an optional holding a hana::type has a
- // nested ::type alias.
- template <typename ...>
- using void_t = void;
- template <typename T, typename = void>
- struct has_type : std::false_type { };
- template <typename T>
- struct has_type<T, void_t<typename T::type>>
- : std::true_type
- { };
- struct T;
- static_assert(std::is_same<decltype(hana::just(hana::type_c<T>))::type, T>{}, "");
- static_assert(!has_type<decltype(hana::nothing)>{}, "");
- int main() { }
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