2021-10-05 21:37:46 +02:00

94 lines
2.7 KiB
C++

// Copyright Louis Dionne 2013-2017
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
#ifndef BOOST_HANA_TEST_LAWS_GROUP_HPP
#define BOOST_HANA_TEST_LAWS_GROUP_HPP
#include <boost/hana/assert.hpp>
#include <boost/hana/bool.hpp>
#include <boost/hana/concept/comparable.hpp>
#include <boost/hana/core/when.hpp>
#include <boost/hana/concept/group.hpp>
#include <boost/hana/lazy.hpp>
#include <laws/base.hpp>
namespace boost { namespace hana { namespace test {
template <typename G, typename = when<true>>
struct TestGroup : TestGroup<G, laws> {
using TestGroup<G, laws>::TestGroup;
};
template <typename G>
struct TestGroup<G, laws> {
template <typename Xs>
TestGroup(Xs xs) {
hana::for_each(xs, [](auto x) {
static_assert(Group<decltype(x)>{}, "");
});
#ifdef BOOST_HANA_WORKAROUND_MSVC_DECLTYPEAUTO_RETURNTYPE_662735
zero<G>(); // force adding zero<G>'s member function to pending temploid list
#endif
foreach2(xs, [](auto x, auto y) {
// left inverse
BOOST_HANA_CHECK(hana::equal(
hana::plus(x, hana::negate(x)),
zero<G>()
));
// right inverse
BOOST_HANA_CHECK(hana::equal(
hana::plus(hana::negate(x), x),
zero<G>()
));
// default definition of minus
BOOST_HANA_CHECK(hana::equal(
hana::minus(x, y),
hana::plus(x, hana::negate(y))
));
BOOST_HANA_CHECK(hana::equal(
hana::minus(y, x),
hana::plus(y, hana::negate(x))
));
// default definition of negate
BOOST_HANA_CHECK(hana::equal(
hana::negate(hana::negate(x)),
x
));
});
}
};
template <typename C>
struct TestGroup<C, when<Constant<C>::value>>
: TestGroup<C, laws>
{
template <typename Xs>
TestGroup(Xs xs) : TestGroup<C, laws>{xs} {
foreach2(xs, [](auto x, auto y) {
BOOST_HANA_CHECK(hana::equal(
hana::negate(hana::value(x)),
hana::value(hana::negate(x))
));
BOOST_HANA_CHECK(hana::equal(
hana::minus(hana::value(x), hana::value(y)),
hana::value(hana::minus(x, y))
));
});
}
};
}}} // end namespace boost::hana::test
#endif // !BOOST_HANA_TEST_LAWS_GROUP_HPP