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/fold_right.hpp>
7 #include <boost/hana/tuple.hpp>
8
9 #include <sstream>
10 #include <string>
11 namespace hana = boost::hana;
12
13
__anone53903c10102(auto x) 14 auto to_string = [](auto x) {
15 std::ostringstream ss;
16 ss << x;
17 return ss.str();
18 };
19
main()20 int main() {
21 auto f = [=](auto element, std::string s) {
22 return "f(" + to_string(element) + ", " + s + ")";
23 };
24
25 // with an initial state
26 BOOST_HANA_RUNTIME_CHECK(
27 hana::fold_right(hana::make_tuple(1, '2', 3.0, 4), "5", f)
28 ==
29 "f(1, f(2, f(3, f(4, 5))))"
30 );
31
32 // without initial state
33 BOOST_HANA_RUNTIME_CHECK(
34 hana::fold_right(hana::make_tuple(1, '2', 3.0, 4, "5"), f)
35 ==
36 "f(1, f(2, f(3, f(4, 5))))"
37 );
38 }
39