| 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/fold_left.hpp> |
| 7 | #include <boost/hana/tuple.hpp> |
| 8 | |
| 9 | #include <sstream> |
| 10 | namespace hana = boost::hana; |
| 11 | |
| 12 | |
| 13 | auto to_string = [](auto x) { |
| 14 | std::ostringstream ss; |
| 15 | ss << x; |
| 16 | return ss.str(); |
| 17 | }; |
| 18 | |
| 19 | auto show = [](auto x, auto y) { |
| 20 | return "("+ to_string(x) + " + "+ to_string(y) + ")"; |
| 21 | }; |
| 22 | |
| 23 | int main() { |
| 24 | BOOST_HANA_RUNTIME_CHECK( |
| 25 | hana::fold_left(hana::make_tuple(2, "3", '4'), "1", show) == "(((1 + 2) + 3) + 4)" |
| 26 | ); |
| 27 | } |
| 28 |