| 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/config.hpp> |
| 7 | #include <boost/hana/functional/fix.hpp> |
| 8 | namespace hana = boost::hana; |
| 9 | |
| 10 | |
| 11 | BOOST_HANA_CONSTEXPR_STATELESS_LAMBDA auto factorial = hana::fix([](auto fact, auto n) -> int { |
| 12 | if (n == 0) return 1; |
| 13 | else return n * fact(n - 1); |
| 14 | }); |
| 15 | |
| 16 | int main() { |
| 17 | BOOST_HANA_CONSTEXPR_CHECK(factorial(5) == 120); |
| 18 | } |
| 19 |