1 | #ifndef BOOST_MP11_DETAIL_MP_FOLD_HPP_INCLUDED |
2 | #define BOOST_MP11_DETAIL_MP_FOLD_HPP_INCLUDED |
3 | |
4 | // Copyright 2015-2017 Peter Dimov. |
5 | // |
6 | // Distributed under the Boost Software License, Version 1.0. |
7 | // |
8 | // See accompanying file LICENSE_1_0.txt or copy at |
9 | // http://www.boost.org/LICENSE_1_0.txt |
10 | |
11 | #include <boost/mp11/detail/config.hpp> |
12 | |
13 | namespace boost |
14 | { |
15 | namespace mp11 |
16 | { |
17 | |
18 | // mp_fold<L, V, F> |
19 | namespace detail |
20 | { |
21 | |
22 | template<class L, class V, template<class...> class F> struct mp_fold_impl |
23 | { |
24 | // An error "no type named 'type'" here means that the first argument to mp_fold is not a list |
25 | }; |
26 | |
27 | #if BOOST_MP11_WORKAROUND( BOOST_MP11_MSVC, <= 1800 ) |
28 | |
29 | template<template<class...> class L, class... T, class V, template<class...> class F> struct mp_fold_impl<L<T...>, V, F> |
30 | { |
31 | static_assert( sizeof...(T) == 0, "T... must be empty" ); |
32 | using type = V; |
33 | }; |
34 | |
35 | #else |
36 | |
37 | template<template<class...> class L, class V, template<class...> class F> struct mp_fold_impl<L<>, V, F> |
38 | { |
39 | using type = V; |
40 | }; |
41 | |
42 | #endif |
43 | |
44 | template<template<class...> class L, class T1, class... T, class V, template<class...> class F> struct mp_fold_impl<L<T1, T...>, V, F> |
45 | { |
46 | using type = typename mp_fold_impl<L<T...>, F<V, T1>, F>::type; |
47 | }; |
48 | |
49 | template<template<class...> class L, class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9, class T10, class... T, class V, template<class...> class F> struct mp_fold_impl<L<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T...>, V, F> |
50 | { |
51 | using type = typename mp_fold_impl<L<T...>, F<F<F<F<F<F<F<F<F<F<V, T1>, T2>, T3>, T4>, T5>, T6>, T7>, T8>, T9>, T10>, F>::type; |
52 | }; |
53 | |
54 | } // namespace detail |
55 | |
56 | template<class L, class V, template<class...> class F> using mp_fold = typename detail::mp_fold_impl<L, V, F>::type; |
57 | template<class L, class V, class Q> using mp_fold_q = mp_fold<L, V, Q::template fn>; |
58 | |
59 | } // namespace mp11 |
60 | } // namespace boost |
61 | |
62 | #endif // #ifndef BOOST_MP11_DETAIL_MP_FOLD_HPP_INCLUDED |
63 | |