drop_front.cpp 1003 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/drop_front.hpp>
  6. #include <boost/hana/equal.hpp>
  7. #include <boost/hana/integral_constant.hpp>
  8. #include <boost/hana/tuple.hpp>
  9. namespace hana = boost::hana;
  10. constexpr auto xs = hana::make_tuple(0, '1', 2.0);
  11. static_assert(hana::drop_front(xs, hana::size_c<0>) == xs, "");
  12. static_assert(hana::drop_front(xs, hana::size_c<1>) == hana::make_tuple('1', 2.0), "");
  13. static_assert(hana::drop_front(xs, hana::size_c<2>) == hana::make_tuple(2.0), "");
  14. BOOST_HANA_CONSTANT_CHECK(hana::drop_front(xs, hana::size_c<3>) == hana::make_tuple());
  15. BOOST_HANA_CONSTANT_CHECK(hana::drop_front(xs, hana::size_c<4>) == hana::make_tuple());
  16. // drop_front(xs) is equivalent to drop_front(xs, size_t<1>)
  17. static_assert(hana::drop_front(xs) == hana::make_tuple('1', 2.0), "");
  18. int main() { }