ceph/src/boost/libs/hana/example/map/difference.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/difference.hpp>
   7 #include <boost/hana/equal.hpp>
   8 #include <boost/hana/map.hpp>
   9 #include <boost/hana/string.hpp>
  10
  11 #include <string>
  12 namespace hana = boost::hana;
  13 using namespace hana::literals;
  14
  15
  16 constexpr auto m1 = hana::make_map(
  17     hana::make_pair("key1"_s, hana::type_c<std::string>),
  18     hana::make_pair("key2"_s, hana::type_c<std::string>)
  19 );
  20
  21 constexpr auto m2 = hana::make_map(
  22     hana::make_pair("key3"_s, hana::type_c<std::string>),
  23     hana::make_pair("key4"_s, hana::type_c<std::string>),
  24     hana::make_pair("key5"_s, hana::type_c<std::string>)
  25 );
  26
  27 constexpr auto m3 = hana::make_map(
  28     hana::make_pair("key1"_s, hana::type_c<std::string>),
  29     hana::make_pair("key4"_s, hana::type_c<int>),
  30     hana::make_pair("key2"_s, hana::type_c<long long>)
  31 );
  32
  33 int main() {
  34     BOOST_HANA_CONSTANT_CHECK(hana::difference(m1, m2) == m1);
  35
  36     BOOST_HANA_CONSTANT_CHECK(hana::difference(m1, m3) == hana::make_map());
  37
  38     BOOST_HANA_CONSTANT_CHECK(hana::difference(m3, m1) == hana::make_map(
  39         hana::make_pair("key4"_s, hana::type_c<int>)
  40     ));
  41
  42     BOOST_HANA_CONSTANT_CHECK(hana::difference(m2, m3) == hana::make_map(
  43         hana::make_pair("key3"_s, hana::type_c<std::string>),
  44         hana::make_pair("key5"_s, hana::type_c<std::string>)
  45     ));
  46 }