ceph/src/boost/libs/hana/test/comparable.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/concept/comparable.hpp>
   7 #include <boost/hana/equal.hpp>
   8 #include <boost/hana/not.hpp>
   9 #include <boost/hana/tuple.hpp>
  10
  11 #include <laws/base.hpp>
  12 #include <laws/comparable.hpp>
  13
  14 #include <type_traits>
  15 namespace hana = boost::hana;
  16
  17
  18 // Minimal EqualityComparable types
  19 struct eq1 { int value; };
  20 struct eq2 {
  21     int value;
  22     constexpr operator eq1() const { return {value}; }
  23 };
  24
  25 template <typename T, typename U, typename = std::enable_if_t<
  26     (std::is_same<T, eq1>{} || std::is_same<T, eq2>{}) &&
  27     (std::is_same<U, eq1>{} || std::is_same<U, eq2>{})
  28 >>
  29 constexpr bool operator==(T a, U b)
  30 { return a.value == b.value; }
  31
  32 template <typename T, typename U, typename = std::enable_if_t<
  33     (std::is_same<T, eq1>{} || std::is_same<T, eq2>{}) &&
  34     (std::is_same<U, eq1>{} || std::is_same<U, eq2>{})
  35 >>
  36 constexpr bool operator!=(T a, U b)
  37 { return !(a == b); }
  38
  39
  40 int main() {
  41     // equal
  42     {
  43         // Two objects of different data types are unequal by default,
  44         // and no model is provided for two objects of the same data type.
  45         struct Random1 { }; struct Random2 { };
  46         BOOST_HANA_CONSTANT_CHECK(hana::not_(hana::equal(Random1{}, Random2{})));
  47         static_assert(!hana::Comparable<Random1>::value, "");
  48         static_assert(!hana::Comparable<Random2>::value, "");
  49
  50         // Provided model for EqualityComparable types
  51         BOOST_HANA_CONSTEXPR_CHECK(hana::equal(eq1{0}, eq1{0}));
  52         BOOST_HANA_CONSTEXPR_CHECK(hana::not_(hana::equal(eq1{0}, eq1{1})));
  53         BOOST_HANA_CONSTEXPR_CHECK(hana::not_(hana::equal(eq1{1}, eq1{0})));
  54
  55         BOOST_HANA_CONSTEXPR_CHECK(hana::equal(eq1{0}, eq2{0}));
  56         BOOST_HANA_CONSTEXPR_CHECK(hana::not_(hana::equal(eq1{0}, eq2{1})));
  57         BOOST_HANA_CONSTEXPR_CHECK(hana::not_(hana::equal(eq1{1}, eq2{0})));
  58
  59         BOOST_HANA_CONSTEXPR_CHECK(hana::equal(eq2{0}, eq1{0}));
  60         BOOST_HANA_CONSTEXPR_CHECK(hana::not_(hana::equal(eq2{0}, eq1{1})));
  61         BOOST_HANA_CONSTEXPR_CHECK(hana::not_(hana::equal(eq2{1}, eq1{0})));
  62     }
  63
  64     // laws
  65     hana::test::TestComparable<int>{hana::make_tuple(0,1,2,3,4,5)};
  66     hana::test::TestComparable<unsigned int>{hana::make_tuple(0u,1u,2u,3u,4u,5u)};
  67     hana::test::TestComparable<long>{hana::make_tuple(0l,1l,2l,3l,4l,5l)};
  68     hana::test::TestComparable<unsigned long>{hana::make_tuple(0ul,1ul,2ul,3ul,4ul,5ul)};
  69     hana::test::TestComparable<eq1>{hana::make_tuple(eq1{0}, eq1{1}, eq1{2}, eq1{3}, eq1{4})};
  70 }