unique.cpp
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// Copyright Louis Dionne 2013-2022
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE.md or copy at http://boost.org/LICENSE_1_0.txt)
#include <boost/hana/assert.hpp>
#include <boost/hana/comparing.hpp>
#include <boost/hana/equal.hpp>
#include <boost/hana/tuple.hpp>
#include <boost/hana/type.hpp>
#include <boost/hana/unique.hpp>
#include <string>
namespace hana = boost::hana;
using namespace std::literals;
// unique without a predicate
constexpr auto types = hana::tuple_t<int, float, float, char, int, int, int, double>;
BOOST_HANA_CONSTANT_CHECK(
hana::unique(types) == hana::tuple_t<int, float, char, int, double>
);
int main() {
// unique with a predicate
auto objects = hana::make_tuple(1, 2, "abc"s, 'd', "efg"s, "hij"s, 3.4f);
BOOST_HANA_RUNTIME_CHECK(
hana::unique(objects, [](auto const& t, auto const& u) {
return hana::typeid_(t) == hana::typeid_(u);
})
== hana::make_tuple(1, "abc"s, 'd', "efg"s, 3.4f)
);
// unique.by is syntactic sugar
BOOST_HANA_RUNTIME_CHECK(
hana::unique.by(hana::comparing(hana::typeid_), objects) ==
hana::make_tuple(1, "abc"s, 'd', "efg"s, 3.4f)
);
}