// BITSET2
//
//  Copyright Claas Bontus
//
//  Use, modification and distribution is subject to the
//  Boost Software License, Version 1.0. (See accompanying
//  file LICENSE.txt or copy at
//  http://www.boost.org/LICENSE_1_0.txt)
//
// Project home: https://github.com/ClaasBontus/bitset2
//

#pragma once

#include "h_types.hpp"

namespace detail
{

template <size_t N, class T>
struct bit_chars {
    using h_t      = h_types<T>;
    using ULONG_t  = typename h_t::ULONG_t;
    using ULLONG_t = typename h_t::ULLONG_t;
    using LRGST_t  = typename h_t::LRGST_t;
    using base_t   = T;

    //
    enum : size_t {
        n_bits       = N,
        ulong_n_bits = h_t::ulong_n_bits   ///< #bits in ULONG_t
        ,
        ullong_n_bits = h_t::ullong_n_bits ///< #bits in ULLONG_t
        ,
        lrgst_n_bist = h_t::lrgst_n_bist   ///< #bits in LRGST_t
        ,
        base_t_n_bits = h_t::base_t_n_bits ///< #bits in T
        ,
        div_val = n_bits / base_t_n_bits,
        mod_val = n_bits % base_t_n_bits,
        n_words = mod_val ? div_val + 1 : div_val ///< #words required
        ,
        n_array = (n_words == 0) ? 1 : n_words    ///< #words used
    };

    enum : ULONG_t { ulong_max = ULONG_MAX };

    enum : base_t {
        all_one         = base_t(~base_t(0)),
        low_bit_pattern = ///< Mask for idx==0
        n_bits == 0                     ? base_t(0)
        : (div_val > 0 || mod_val == 0) ? all_one
                                        : ce_right_shift(all_one, base_t_n_bits - mod_val),
        hgh_bit_pattern = ///< Mask for idx+1==n_words
        n_bits == 0    ? base_t(0)
        : mod_val == 0 ? all_one
                       : ce_right_shift(all_one, base_t_n_bits - mod_val)
    };
}; // struct bit_chars

} // namespace detail