monad_plus.cpp 731 B

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  1. // Copyright Louis Dionne 2013-2017
  2. // Distributed under the Boost Software License, Version 1.0.
  3. // (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
  4. #include <boost/hana/assert.hpp>
  5. #include <boost/hana/concat.hpp>
  6. #include <boost/hana/empty.hpp>
  7. #include <boost/hana/equal.hpp>
  8. #include <boost/hana/optional.hpp>
  9. namespace hana = boost::hana;
  10. static_assert(hana::concat(hana::nothing, hana::just('x')) == hana::just('x'), "");
  11. BOOST_HANA_CONSTANT_CHECK(hana::concat(hana::nothing, hana::nothing) == hana::nothing);
  12. static_assert(hana::concat(hana::just('x'), hana::just('y')) == hana::just('x'), "");
  13. BOOST_HANA_CONSTANT_CHECK(hana::empty<hana::optional_tag>() == hana::nothing);
  14. int main() { }