libs/hana/test/concept/struct/keys.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/concept/struct.hpp>
   7 #include <boost/hana/equal.hpp>
   8 #include <boost/hana/integral_constant.hpp>
   9 #include <boost/hana/keys.hpp>
  10
  11 #include "minimal_struct.hpp"
  12 #include <laws/base.hpp>
  13 #include <support/seq.hpp>
  14 namespace hana = boost::hana;
  15 using hana::test::ct_eq;
  16
  17
  18 template <int i = 0>
  19 struct undefined { };
  20
  21 int main() {
  22     BOOST_HANA_CONSTANT_CHECK(hana::equal(
  23         hana::keys(obj()),
  24         ::seq()
  25     ));
  26
  27     BOOST_HANA_CONSTANT_CHECK(hana::equal(
  28         hana::keys(obj(undefined<0>{})),
  29         ::seq(hana::int_c<0>)
  30     ));
  31
  32     BOOST_HANA_CONSTANT_CHECK(hana::equal(
  33         hana::keys(obj(undefined<0>{}, undefined<1>{})),
  34         ::seq(hana::int_c<0>, hana::int_c<1>)
  35     ));
  36
  37     BOOST_HANA_CONSTANT_CHECK(hana::equal(
  38         hana::keys(obj(undefined<0>{}, undefined<1>{}, undefined<2>{})),
  39         ::seq(hana::int_c<0>, hana::int_c<1>, hana::int_c<2>)
  40     ));
  41
  42     BOOST_HANA_CONSTANT_CHECK(hana::equal(
  43         hana::keys(obj(undefined<0>{}, undefined<1>{}, undefined<2>{}, undefined<3>{})),
  44         ::seq(hana::int_c<0>, hana::int_c<1>, hana::int_c<2>, hana::int_c<3>)
  45     ));
  46 }