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// 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)
#include <boost/hana/functional/overload_linearly.hpp>
#include <boost/hana/assert.hpp>
#include <boost/hana/equal.hpp>
#include <laws/base.hpp>
namespace hana = boost::hana;
using hana::test::ct_eq;
struct A { };
struct AA : A { };
struct B { };
struct C { };
int main() {
// 2 functions without overlap
{
auto f = hana::overload_linearly(
[](A) { return ct_eq<0>{}; },
[](B) { return ct_eq<1>{}; }
);
BOOST_HANA_CONSTANT_CHECK(hana::equal(
f(A{}),
ct_eq<0>{}
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
f(AA{}),
f(A{})
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
f(B{}),
ct_eq<1>{}
));
}
// 2 functions with overlap
{
auto f = hana::overload_linearly(
[](A) { return ct_eq<0>{}; },
[](A) { return ct_eq<1>{}; }
);
auto g = hana::overload_linearly(
[](A) { return ct_eq<0>{}; },
[](AA) { return ct_eq<1>{}; }
);
BOOST_HANA_CONSTANT_CHECK(hana::equal(
f(A{}),
ct_eq<0>{}
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
f(AA{}),
f(A{})
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
g(A{}),
ct_eq<0>{}
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
g(AA{}),
g(A{})
));
}
// 3 functions
{
auto f = hana::overload_linearly(
[](A) { return ct_eq<0>{}; },
[](B) { return ct_eq<1>{}; },
[](C) { return ct_eq<2>{}; }
);
BOOST_HANA_CONSTANT_CHECK(hana::equal(
f(A{}),
ct_eq<0>{}
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
f(AA{}),
f(A{})
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
f(B{}),
ct_eq<1>{}
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
f(C{}),
ct_eq<2>{}
));
}
// 1 function (github issue #280)
{
auto f = hana::overload_linearly(
[](A) { return ct_eq<0>{}; }
);
BOOST_HANA_CONSTANT_CHECK(hana::equal(
f(A{}),
ct_eq<0>{}
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
f(AA{}),
f(A{})
));
}
}
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