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/detail/variadic/foldl1.hpp>
6
7
8 template <typename ...xs>
9 struct list { };
10
11 template <typename T>
12 struct basic_type { using type = T; };
13
14 template <typename T>
15 constexpr basic_type<T> type{};
16
17
18 template <typename F, typename State, typename ...Xs>
foldl(F f,State s,list<Xs...> xs)19 constexpr auto foldl(F f, State s, list<Xs...> xs)
20 { return boost::hana::detail::variadic::foldl(f, s, type<Xs>...); }
21
22 //////////////////////////////////////////////////////////////////////////////
23
24 struct f {
25 template <typename ...>
26 struct result { };
27
28 template <typename X, typename Y>
operator ()f29 constexpr auto operator()(X, Y) const
30 { return result<X, Y>{}; }
31 };
32
33 template <int> struct x { };
34 struct state { };
35
main()36 int main() {
37 constexpr auto xs = list<
38 <%= (1..input_size).map { |i| "x<#{i}>" }.join(', ') %>
39 >{};
40
41 constexpr auto result = foldl(f{}, state{}, xs);
42 (void)result;
43 }
44