1 // Copyright Louis Dionne 2013-2017
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/ext/std/integer_sequence.hpp>
7 #include <boost/hana/unpack.hpp>
8
9 #include <tuple>
10 #include <utility>
11 namespace hana = boost::hana;
12
13
__anon0a1c5bad0102(auto a, auto b, auto c) 14 auto add = [](auto a, auto b, auto c) { return a + b + c; };
15
main()16 int main() {
17 std::tuple<int, long, double> tuple{1, 2l, 3.3};
18
19 auto sum = hana::unpack(std::integer_sequence<int, 0, 1, 2>{}, [&](auto ...i) {
20 // the `i`s are `std::integral_constant<int, ...>`s
21 return add(std::get<decltype(i)::value>(tuple)...);
22 });
23
24 BOOST_HANA_RUNTIME_CHECK(sum == 6.3);
25 }
26