ceph/src/boost/libs/hana/test/tuple/at.const.cpp

   1 // Copyright Louis Dionne 2013-2016
   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/tuple.hpp>
   7
   8 #include <string>
   9 namespace hana = boost::hana;
  10
  11
  12 struct Empty { };
  13
  14 int main() {
  15     {
  16         using T = hana::tuple<int>;
  17         const T t(3);
  18         BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == 3);
  19     }
  20     {
  21         using T = hana::tuple<std::string, int>;
  22         const T t("high", 5);
  23         BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == "high");
  24         BOOST_HANA_RUNTIME_CHECK(hana::at_c<1>(t) == 5);
  25     }
  26     {
  27         using T = hana::tuple<double, int>;
  28         constexpr T t(2.718, 5);
  29         static_assert(hana::at_c<0>(t) == 2.718, "");
  30         static_assert(hana::at_c<1>(t) == 5, "");
  31     }
  32     {
  33         using T = hana::tuple<Empty>;
  34         constexpr T t{Empty()};
  35         constexpr Empty e = hana::at_c<0>(t); (void)e;
  36     }
  37     {
  38         using T = hana::tuple<double&, std::string, int>;
  39         double d = 1.5;
  40         const T t(d, "high", 5);
  41         BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == 1.5);
  42         BOOST_HANA_RUNTIME_CHECK(hana::at_c<1>(t) == "high");
  43         BOOST_HANA_RUNTIME_CHECK(hana::at_c<2>(t) == 5);
  44         hana::at_c<0>(t) = 2.5;
  45         BOOST_HANA_RUNTIME_CHECK(hana::at_c<0>(t) == 2.5);
  46         BOOST_HANA_RUNTIME_CHECK(hana::at_c<1>(t) == "high");
  47         BOOST_HANA_RUNTIME_CHECK(hana::at_c<2>(t) == 5);
  48         BOOST_HANA_RUNTIME_CHECK(d == 2.5);
  49     }
  50 }