1 #ifndef BOOST_MP11_DETAIL_MP_COUNT_HPP_INCLUDED
2 #define BOOST_MP11_DETAIL_MP_COUNT_HPP_INCLUDED
4 // Copyright 2015, 2016 Peter Dimov.
6 // Distributed under the Boost Software License, Version 1.0.
8 // See accompanying file LICENSE_1_0.txt or copy at
9 // http://www.boost.org/LICENSE_1_0.txt
11 #include <boost/mp11/integral.hpp>
12 #include <boost/mp11/detail/mp_plus.hpp>
13 #include <boost/mp11/detail/config.hpp>
24 template<class L, class V> struct mp_count_impl;
26 #if defined( BOOST_MP11_HAS_FOLD_EXPRESSIONS )
28 template<template<class...> class L, class... T, class V> struct mp_count_impl<L<T...>, V>
30 using type = mp_size_t<(std::is_same<T, V>::value + ... + 0)>;
33 #elif !defined( BOOST_MP11_NO_CONSTEXPR )
35 constexpr std::size_t cx_plus()
40 template<class T1, class... T> constexpr std::size_t cx_plus(T1 t1, T... t)
42 return static_cast<std::size_t>(t1) + cx_plus(t...);
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)
48 return static_cast<std::size_t>(t1 + t2 + t3 + t4 + t5 + t6 + t7 + t8 + t9 + t10) + cx_plus(t...);
51 template<template<class...> class L, class... T, class V> struct mp_count_impl<L<T...>, V>
53 using type = mp_size_t<cx_plus(std::is_same<T, V>::value...)>;
58 template<template<class...> class L, class... T, class V> struct mp_count_impl<L<T...>, V>
60 using type = mp_size_t<mp_plus<std::is_same<T, V>...>::value>;
67 template<class L, class V> using mp_count = typename detail::mp_count_impl<L, V>::type;
73 template<class L, template<class...> class P> struct mp_count_if_impl;
75 #if defined( BOOST_MP11_HAS_FOLD_EXPRESSIONS ) && !BOOST_MP11_WORKAROUND( BOOST_MP11_MSVC, < 1920 )
77 template<template<class...> class L, class... T, template<class...> class P> struct mp_count_if_impl<L<T...>, P>
79 using type = mp_size_t<(mp_to_bool<P<T>>::value + ... + 0)>;
82 #elif !defined( BOOST_MP11_NO_CONSTEXPR )
84 template<template<class...> class L, class... T, template<class...> class P> struct mp_count_if_impl<L<T...>, P>
86 using type = mp_size_t<cx_plus(mp_to_bool<P<T>>::value...)>;
91 template<template<class...> class L, class... T, template<class...> class P> struct mp_count_if_impl<L<T...>, P>
93 #if BOOST_MP11_WORKAROUND( BOOST_MP11_MSVC, < 1920 )
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>;
100 using type = mp_size_t<mp_plus<mp_to_bool<P<T>>...>::value>;
107 } // namespace detail
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>;
115 #endif // #ifndef BOOST_MP11_DETAIL_MP_COUNT_HPP_INCLUDED