ceph/src/boost/libs/hana/test/experimental/view/sliced/is_empty.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/experimental/view.hpp>
   7 #include <boost/hana/is_empty.hpp>
   8 #include <boost/hana/not.hpp>
   9 #include <boost/hana/tuple.hpp>
  10
  11 #include <support/seq.hpp>
  12 namespace hana = boost::hana;
  13
  14
  15 template <int> struct undefined { };
  16
  17 int main() {
  18     auto container = ::seq;
  19
  20     {
  21         auto storage = container();
  22         auto sliced = hana::experimental::sliced(storage, hana::tuple_c<int>);
  23         BOOST_HANA_CONSTANT_CHECK(hana::is_empty(sliced));
  24     }{
  25         auto storage = container(undefined<0>{});
  26         auto sliced = hana::experimental::sliced(storage, hana::tuple_c<int>);
  27         BOOST_HANA_CONSTANT_CHECK(hana::is_empty(sliced));
  28     }{
  29         auto storage = container(undefined<0>{}, undefined<1>{});
  30         auto sliced = hana::experimental::sliced(storage, hana::tuple_c<int>);
  31         BOOST_HANA_CONSTANT_CHECK(hana::is_empty(sliced));
  32     }
  33
  34     {
  35         auto storage = container(undefined<0>{});
  36         auto sliced = hana::experimental::sliced(storage, hana::tuple_c<int, 0>);
  37         BOOST_HANA_CONSTANT_CHECK(hana::not_(hana::is_empty(sliced)));
  38     }{
  39         auto storage = container(undefined<0>{});
  40         auto sliced = hana::experimental::sliced(storage, hana::tuple_c<int, 0, 0>);
  41         BOOST_HANA_CONSTANT_CHECK(hana::not_(hana::is_empty(sliced)));
  42     }
  43
  44     {
  45         auto storage = container(undefined<0>{}, undefined<1>{});
  46         auto sliced = hana::experimental::sliced(storage, hana::tuple_c<int, 0, 1>);
  47         BOOST_HANA_CONSTANT_CHECK(hana::not_(hana::is_empty(sliced)));
  48     }
  49 }