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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/assert.hpp>
#include <boost/hana/equal.hpp>
#include <boost/hana/fold_left.hpp>
#include <boost/hana/tuple.hpp>
#include <boost/hana/type.hpp>
namespace hana = boost::hana;
template <typename ...>
struct F { struct type; };
struct x0;
struct x1;
struct x2;
struct x3;
int main() {
// tuple_t and initial state
{
auto f = hana::metafunction<F>;
auto s = hana::type_c<struct initial_state>;
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::fold_left(hana::tuple_t<>, s, f),
s
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::fold_left(hana::tuple_t<x0>, s, f),
f(s, hana::type_c<x0>)
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::fold_left(hana::tuple_t<x0, x1>, s, f),
f(f(s, hana::type_c<x0>), hana::type_c<x1>)
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::fold_left(hana::tuple_t<x0, x1, x2>, s, f),
f(f(f(s, hana::type_c<x0>), hana::type_c<x1>), hana::type_c<x2>)
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::fold_left(hana::tuple_t<x0, x1, x2, x3>, s, f),
f(f(f(f(s, hana::type_c<x0>), hana::type_c<x1>), hana::type_c<x2>), hana::type_c<x3>)
));
}
// tuple_t and no initial state
{
auto f = hana::metafunction<F>;
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::fold_left(hana::tuple_t<x0>, f),
hana::type_c<x0>
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::fold_left(hana::tuple_t<x0, x1>, f),
f(hana::type_c<x0>, hana::type_c<x1>)
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::fold_left(hana::tuple_t<x0, x1, x2>, f),
f(f(hana::type_c<x0>, hana::type_c<x1>), hana::type_c<x2>)
));
BOOST_HANA_CONSTANT_CHECK(hana::equal(
hana::fold_left(hana::tuple_t<x0, x1, x2, x3>, f),
f(f(f(hana::type_c<x0>, hana::type_c<x1>), hana::type_c<x2>), hana::type_c<x3>)
));
}
}
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