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/equal.hpp>
7 #include <boost/hana/scan_left.hpp>
8 #include <boost/hana/tuple.hpp>
9
10 #include <sstream>
11 namespace hana = boost::hana;
12
13
__anonde50e76e0102(auto x) 14 auto to_string = [](auto x) {
15 std::ostringstream ss;
16 ss << x;
17 return ss.str();
18 };
19
__anonde50e76e0202(auto state, auto element) 20 auto f = [](auto state, auto element) {
21 return "f(" + to_string(state) + ", " + to_string(element) + ")";
22 };
23
main()24 int main() {
25 // with initial state
26 BOOST_HANA_RUNTIME_CHECK(hana::scan_left(hana::make_tuple(2, "3", '4'), 1, f) == hana::make_tuple(
27 1,
28 "f(1, 2)",
29 "f(f(1, 2), 3)",
30 "f(f(f(1, 2), 3), 4)"
31 ));
32
33 // without initial state
34 BOOST_HANA_RUNTIME_CHECK(hana::scan_left(hana::make_tuple(1, "2", '3'), f) == hana::make_tuple(
35 1,
36 "f(1, 2)",
37 "f(f(1, 2), 3)"
38 ));
39 }
40