ceph/src/boost/libs/hana/test/optional/find_if.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/equal.hpp>
   7 #include <boost/hana/find_if.hpp>
   8 #include <boost/hana/optional.hpp>
   9
  10 #include <laws/base.hpp>
  11 namespace hana = boost::hana;
  12 using hana::test::ct_eq;
  13
  14
  15 int main() {
  16     ct_eq<2> x{};
  17     ct_eq<3> y{};
  18
  19     BOOST_HANA_CONSTANT_CHECK(hana::equal(
  20         hana::find_if(hana::just(x), hana::equal.to(x)),
  21         hana::just(x)
  22     ));
  23     BOOST_HANA_CONSTANT_CHECK(hana::equal(
  24         hana::find_if(hana::just(x), hana::equal.to(y)),
  25         hana::nothing
  26     ));
  27     BOOST_HANA_CONSTANT_CHECK(hana::equal(
  28         hana::find_if(hana::nothing, hana::equal.to(x)),
  29         hana::nothing
  30     ));
  31
  32     // Previously, there was a bug that would make this fail.
  33     auto non_const_nothing = hana::nothing;
  34     BOOST_HANA_CONSTANT_CHECK(hana::equal(
  35         hana::find_if(non_const_nothing, hana::equal.to(x)),
  36         hana::nothing
  37     ));
  38 }