libs/hana/test/ext/std/integer_sequence/front.cpp

   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
   5 #include <boost/hana/assert.hpp>
   6 #include <boost/hana/equal.hpp>
   7 #include <boost/hana/ext/std/integer_sequence.hpp>
   8 #include <boost/hana/ext/std/integral_constant.hpp>
   9 #include <boost/hana/front.hpp>
  10
  11 #include <type_traits>
  12 #include <utility>
  13 namespace hana = boost::hana;
  14
  15
  16 int main() {
  17     BOOST_HANA_CONSTANT_CHECK(hana::equal(
  18         hana::front(std::index_sequence<0>{}),
  19         std::integral_constant<std::size_t, 0>{}
  20     ));
  21
  22     BOOST_HANA_CONSTANT_CHECK(hana::equal(
  23         hana::front(std::index_sequence<0, 1>{}),
  24         std::integral_constant<std::size_t, 0>{}
  25     ));
  26
  27     BOOST_HANA_CONSTANT_CHECK(hana::equal(
  28         hana::front(std::integer_sequence<int, -3, 1, 2, 3, 4>{}),
  29         std::integral_constant<int, -3>{}
  30     ));
  31 }