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31 lines
1.0 KiB
C++
31 lines
1.0 KiB
C++
/*
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@copyright Louis Dionne 2014
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Distributed under the Boost Software License, Version 1.0.
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(See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
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*/
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#include <boost/hana/maybe.hpp>
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#include <boost/hana/detail/constexpr.hpp>
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#include <boost/hana/detail/laws.hpp>
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#include <boost/hana/detail/static_assert.hpp>
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#include <boost/hana/integral.hpp>
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using namespace boost::hana;
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int main() {
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BOOST_HANA_STATIC_ASSERT(join(nothing) == nothing);
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BOOST_HANA_STATIC_ASSERT(join(just(nothing)) == nothing);
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BOOST_HANA_STATIC_ASSERT(join(just(just(int_<3>))) == just(int_<3>));
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BOOST_HANA_CONSTEXPR_LAMBDA auto f = [](auto x) { return just(x + int_<1>); };
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BOOST_HANA_CONSTEXPR_LAMBDA auto g = [](auto x) { return just(x * int_<3>); };
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BOOST_HANA_CONSTEXPR_LAMBDA auto check_monad_laws = [=](auto x) {
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BOOST_HANA_STATIC_ASSERT(detail::laws<Monad>(x, int_<1>, f, g));
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};
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check_monad_laws(nothing);
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check_monad_laws(just(int_<1>));
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check_monad_laws(just(1));
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}
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