1 | #ifndef BOOST_MP11_DETAIL_MP_COUNT_HPP_INCLUDED |
2 | #define BOOST_MP11_DETAIL_MP_COUNT_HPP_INCLUDED |
3 | |
4 | // Copyright 2015, 2016 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/integral.hpp> |
12 | #include <boost/mp11/detail/mp_plus.hpp> |
13 | #include <boost/mp11/detail/config.hpp> |
14 | |
15 | namespace boost |
16 | { |
17 | namespace mp11 |
18 | { |
19 | |
20 | // mp_count<L, V> |
21 | namespace detail |
22 | { |
23 | |
24 | template<class L, class V> struct mp_count_impl; |
25 | |
26 | #if defined( BOOST_MP11_HAS_FOLD_EXPRESSIONS ) |
27 | |
28 | template<template<class...> class L, class... T, class V> struct mp_count_impl<L<T...>, V> |
29 | { |
30 | using type = mp_size_t<(std::is_same<T, V>::value + ... + 0)>; |
31 | }; |
32 | |
33 | #elif !defined( BOOST_MP11_NO_CONSTEXPR ) |
34 | |
35 | constexpr std::size_t cx_plus() |
36 | { |
37 | return 0; |
38 | } |
39 | |
40 | template<class T1, class... T> constexpr std::size_t cx_plus(T1 t1, T... t) |
41 | { |
42 | return static_cast<std::size_t>(t1) + cx_plus(t...); |
43 | } |
44 | |
45 | template<class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9, class T10, class... T> |
46 | constexpr std::size_t cx_plus(T1 t1, T2 t2, T3 t3, T4 t4, T5 t5, T6 t6, T7 t7, T8 t8, T9 t9, T10 t10, T... t) |
47 | { |
48 | return static_cast<std::size_t>(t1 + t2 + t3 + t4 + t5 + t6 + t7 + t8 + t9 + t10) + cx_plus(t...); |
49 | } |
50 | |
51 | template<template<class...> class L, class... T, class V> struct mp_count_impl<L<T...>, V> |
52 | { |
53 | using type = mp_size_t<cx_plus(std::is_same<T, V>::value...)>; |
54 | }; |
55 | |
56 | #else |
57 | |
58 | template<template<class...> class L, class... T, class V> struct mp_count_impl<L<T...>, V> |
59 | { |
60 | using type = mp_size_t<mp_plus<std::is_same<T, V>...>::value>; |
61 | }; |
62 | |
63 | #endif |
64 | |
65 | } // namespace detail |
66 | |
67 | template<class L, class V> using mp_count = typename detail::mp_count_impl<L, V>::type; |
68 | |
69 | // mp_count_if<L, P> |
70 | namespace detail |
71 | { |
72 | |
73 | template<class L, template<class...> class P> struct mp_count_if_impl; |
74 | |
75 | #if defined( BOOST_MP11_HAS_FOLD_EXPRESSIONS ) && !BOOST_MP11_WORKAROUND( BOOST_MP11_MSVC, < 1920 ) |
76 | |
77 | template<template<class...> class L, class... T, template<class...> class P> struct mp_count_if_impl<L<T...>, P> |
78 | { |
79 | using type = mp_size_t<(mp_to_bool<P<T>>::value + ... + 0)>; |
80 | }; |
81 | |
82 | #elif !defined( BOOST_MP11_NO_CONSTEXPR ) |
83 | |
84 | template<template<class...> class L, class... T, template<class...> class P> struct mp_count_if_impl<L<T...>, P> |
85 | { |
86 | using type = mp_size_t<cx_plus(mp_to_bool<P<T>>::value...)>; |
87 | }; |
88 | |
89 | #else |
90 | |
91 | template<template<class...> class L, class... T, template<class...> class P> struct mp_count_if_impl<L<T...>, P> |
92 | { |
93 | #if BOOST_MP11_WORKAROUND( BOOST_MP11_MSVC, < 1920 ) |
94 | |
95 | template<class T> struct _f { using type = mp_to_bool<P<T>>; }; |
96 | using type = mp_size_t<mp_plus<typename _f<T>::type...>::value>; |
97 | |
98 | #else |
99 | |
100 | using type = mp_size_t<mp_plus<mp_to_bool<P<T>>...>::value>; |
101 | |
102 | #endif |
103 | }; |
104 | |
105 | #endif |
106 | |
107 | } // namespace detail |
108 | |
109 | template<class L, template<class...> class P> using mp_count_if = typename detail::mp_count_if_impl<L, P>::type; |
110 | template<class L, class Q> using mp_count_if_q = mp_count_if<L, Q::template fn>; |
111 | |
112 | } // namespace mp11 |
113 | } // namespace boost |
114 | |
115 | #endif // #ifndef BOOST_MP11_DETAIL_MP_COUNT_HPP_INCLUDED |
116 | |