Hu Chunming / sip_server

#ifndef BOOST_LEAF_DETAIL_MP11_HPP_INCLUDED
#define BOOST_LEAF_DETAIL_MP11_HPP_INCLUDED

//  Copyright 2015-2017 Peter Dimov.
//  Copyright 2018-2022 Emil Dotchevski and Reverge Studios, Inc.
//
//  Distributed under the Boost Software License, Version 1.0.
//
//  See accompanying file LICENSE_1_0.txt or copy at
//  http://www.boost.org/LICENSE_1_0.txt

#include <type_traits>
#include <cstddef>

namespace boost { namespace leaf { namespace leaf_detail_mp11 {

// mp_list<T...>
template<class... T> struct mp_list
{
};

// mp_identity
template<class T> struct mp_identity
{
    using type = T;
};

// mp_inherit
template<class... T> struct mp_inherit: T... {};

// mp_if, mp_if_c
namespace detail
{

template<bool C, class T, class... E> struct mp_if_c_impl
{
};

template<class T, class... E> struct mp_if_c_impl<true, T, E...>
{
    using type = T;
};

template<class T, class E> struct mp_if_c_impl<false, T, E>
{
    using type = E;
};

} // namespace detail

template<bool C, class T, class... E> using mp_if_c = typename detail::mp_if_c_impl<C, T, E...>::type;
template<class C, class T, class... E> using mp_if = typename detail::mp_if_c_impl<static_cast<bool>(C::value), T, E...>::type;

// mp_bool
template<bool B> using mp_bool = std::integral_constant<bool, B>;

using mp_true = mp_bool<true>;
using mp_false = mp_bool<false>;

// mp_to_bool
template<class T> using mp_to_bool = mp_bool<static_cast<bool>( T::value )>;

// mp_not<T>
template<class T> using mp_not = mp_bool< !T::value >;

// mp_int
template<int I> using mp_int = std::integral_constant<int, I>;

// mp_size_t
template<std::size_t N> using mp_size_t = std::integral_constant<std::size_t, N>;

// mp_set_contains<S, V>
namespace detail
{

template<class S, class V> struct mp_set_contains_impl;

template<template<class...> class L, class... T, class V> struct mp_set_contains_impl<L<T...>, V>
{
    using type = mp_to_bool<std::is_base_of<mp_identity<V>, mp_inherit<mp_identity<T>...> > >;
};

} // namespace detail

template<class S, class V> using mp_set_contains = typename detail::mp_set_contains_impl<S, V>::type;

// mp_set_push_back<S, T...>
namespace detail
{

template<class S, class... T> struct mp_set_push_back_impl;

template<template<class...> class L, class... U> struct mp_set_push_back_impl<L<U...>>
{
    using type = L<U...>;
};

template<template<class...> class L, class... U, class T1, class... T> struct mp_set_push_back_impl<L<U...>, T1, T...>
{
    using S = mp_if<mp_set_contains<L<U...>, T1>, L<U...>, L<U..., T1>>;
    using type = typename mp_set_push_back_impl<S, T...>::type;
};

} // namespace detail

template<class S, class... T> using mp_set_push_back = typename detail::mp_set_push_back_impl<S, T...>::type;

// mp_unique<L>
namespace detail
{

template<class L> struct mp_unique_impl;

template<template<class...> class L, class... T> struct mp_unique_impl<L<T...>>
{
    using type = mp_set_push_back<L<>, T...>;
};

} // namespace detail

template<class L> using mp_unique = typename detail::mp_unique_impl<L>::type;

// mp_append<L...>

namespace detail
{

template<class... L> struct mp_append_impl;

template<> struct mp_append_impl<>
{
    using type = mp_list<>;
};

template<template<class...> class L, class... T> struct mp_append_impl<L<T...>>
{
    using type = L<T...>;
};

template<template<class...> class L1, class... T1, template<class...> class L2, class... T2, class... Lr> struct mp_append_impl<L1<T1...>, L2<T2...>, Lr...>
{
    using type = typename mp_append_impl<L1<T1..., T2...>, Lr...>::type;
};

}

template<class... L> using mp_append = typename detail::mp_append_impl<L...>::type;

// mp_front<L>
namespace detail
{

template<class L> struct mp_front_impl
{
// An error "no type named 'type'" here means that the argument to mp_front
// is either not a list, or is an empty list
};

template<template<class...> class L, class T1, class... T> struct mp_front_impl<L<T1, T...>>
{
    using type = T1;
};

} // namespace detail

template<class L> using mp_front = typename detail::mp_front_impl<L>::type;

// mp_pop_front<L>
namespace detail
{

template<class L> struct mp_pop_front_impl
{
// An error "no type named 'type'" here means that the argument to mp_pop_front
// is either not a list, or is an empty list
};

template<template<class...> class L, class T1, class... T> struct mp_pop_front_impl<L<T1, T...>>
{
    using type = L<T...>;
};

} // namespace detail

template<class L> using mp_pop_front = typename detail::mp_pop_front_impl<L>::type;

// mp_first<L>
template<class L> using mp_first = mp_front<L>;

// mp_rest<L>
template<class L> using mp_rest = mp_pop_front<L>;

// mp_remove_if<L, P>
namespace detail
{

template<class L, template<class...> class P> struct mp_remove_if_impl;

template<template<class...> class L, class... T, template<class...> class P> struct mp_remove_if_impl<L<T...>, P>
{
    template<class U> using _f = mp_if<P<U>, mp_list<>, mp_list<U>>;
    using type = mp_append<L<>, _f<T>...>;
};

} // namespace detail

template<class L, template<class...> class P> using mp_remove_if = typename detail::mp_remove_if_impl<L, P>::type;

// integer_sequence
template<class T, T... I> struct integer_sequence
{
};

// detail::make_integer_sequence_impl
namespace detail
{

// iseq_if_c
template<bool C, class T, class E> struct iseq_if_c_impl;

template<class T, class E> struct iseq_if_c_impl<true, T, E>
{
    using type = T;
};

template<class T, class E> struct iseq_if_c_impl<false, T, E>
{
    using type = E;
};

template<bool C, class T, class E> using iseq_if_c = typename iseq_if_c_impl<C, T, E>::type;

// iseq_identity
template<class T> struct iseq_identity
{
    using type = T;
};

template<class S1, class S2> struct append_integer_sequence;

template<class T, T... I, T... J> struct append_integer_sequence<integer_sequence<T, I...>, integer_sequence<T, J...>>
{
    using type = integer_sequence< T, I..., ( J + sizeof...(I) )... >;
};

template<class T, T N> struct make_integer_sequence_impl;

template<class T, T N> struct make_integer_sequence_impl_
{
private:

    static_assert( N >= 0, "make_integer_sequence<T, N>: N must not be negative" );

    static T const M = N / 2;
    static T const R = N % 2;

    using S1 = typename make_integer_sequence_impl<T, M>::type;
    using S2 = typename append_integer_sequence<S1, S1>::type;
    using S3 = typename make_integer_sequence_impl<T, R>::type;
    using S4 = typename append_integer_sequence<S2, S3>::type;

public:

    using type = S4;
};

template<class T, T N> struct make_integer_sequence_impl: iseq_if_c<N == 0, iseq_identity<integer_sequence<T>>, iseq_if_c<N == 1, iseq_identity<integer_sequence<T, 0>>, make_integer_sequence_impl_<T, N> > >
{
};

} // namespace detail

// make_integer_sequence
template<class T, T N> using make_integer_sequence = typename detail::make_integer_sequence_impl<T, N>::type;

// index_sequence
template<std::size_t... I> using index_sequence = integer_sequence<std::size_t, I...>;

// make_index_sequence
template<std::size_t N> using make_index_sequence = make_integer_sequence<std::size_t, N>;

// index_sequence_for
template<class... T> using index_sequence_for = make_integer_sequence<std::size_t, sizeof...(T)>;

// implementation by Bruno Dutra (by the name is_evaluable)
namespace detail
{

template<template<class...> class F, class... T> struct mp_valid_impl
{
    template<template<class...> class G, class = G<T...>> static mp_true check(int);
    template<template<class...> class> static mp_false check(...);

    using type = decltype(check<F>(0));
};

} // namespace detail

template<template<class...> class F, class... T> using mp_valid = typename detail::mp_valid_impl<F, T...>::type;

} } }

#endif