1// Copyright Louis Dionne 2013-2022
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/core/make.hpp>
7#include <boost/hana/core/tag_of.hpp>
8#include <boost/hana/equal.hpp>
9#include <boost/hana/integral_constant.hpp>
10#include <boost/hana/range.hpp>
11#include <boost/hana/unpack.hpp>
12
13#include <laws/base.hpp>
14
15#include <type_traits>
16namespace hana = boost::hana;
17
18
19int main() {
20 hana::test::_injection<0> f{};
21
22 BOOST_HANA_CONSTANT_CHECK(hana::equal(
23 hana::unpack(hana::make_range(hana::int_c<0>, hana::int_c<0>), f),
24 f()
25 ));
26 BOOST_HANA_CONSTANT_CHECK(hana::equal(
27 hana::unpack(hana::make_range(hana::int_c<0>, hana::int_c<1>), f),
28 f(hana::int_c<0>)
29 ));
30 BOOST_HANA_CONSTANT_CHECK(hana::equal(
31 hana::unpack(hana::make_range(hana::int_c<0>, hana::int_c<2>), f),
32 f(hana::int_c<0>, hana::int_c<1>)
33 ));
34 BOOST_HANA_CONSTANT_CHECK(hana::equal(
35 hana::unpack(hana::make_range(hana::int_c<0>, hana::int_c<3>), f),
36 f(hana::int_c<0>, hana::int_c<1>, hana::int_c<2>)
37 ));
38
39 // Previously, we would only unpack with `std::size_t`s. Make
40 // sure this does not happen.
41 hana::unpack(hana::make_range(hana::int_c<0>, hana::int_c<1>), [](auto x) {
42 using T = hana::tag_of_t<decltype(x)>;
43 static_assert(std::is_same<typename T::value_type, int>{}, "");
44 });
45}
46

source code of boost/libs/hana/test/range/unpack.cpp