hashset.h

/*
 This Source Code Form is subject to the terms of the Mozilla Public
 License, v. 2.0. If a copy of the MPL was not distributed with this
 file, You can obtain one at http://mozilla.org/MPL/2.0/.
 \author Auberval Florian
*/
 
#pragma once
 
#include "../defines.h"
#include "./iteratorUtils.h"
#include <utility>
 
namespace Ponca
{
    template <int N, typename T = int>
    struct HashDefaultFunctor
    {
        PONCA_MULTIARCH [[nodiscard]] static constexpr T hash(const int _x)
        {
            PONCA_MULTIARCH_STD_MATH(abs);
            return (abs(_x) * 2654435761u) % N;
        }
    };
 
    template <int N, typename T = int, template <int, typename> typename _HashFunctor = HashDefaultFunctor,
              T OFFSET = T(1)>
    class HashSet
    {
        static_assert(N > 0, "The capacity must be strictly positive");
        using HashFunctor    = _HashFunctor<N, T>;
        using container_type = std::array<T, N>;
        using iterator       = typename container_type::iterator;
        using const_iterator = typename container_type::const_iterator;
        using Self           = HashSet<N, T, _HashFunctor, OFFSET>;
 
    protected:
        PONCA_MULTIARCH [[nodiscard]] inline bool search(T _value, T& _searchedIdx) const;
 
    public:
        constexpr PONCA_MULTIARCH HashSet() : m_data() {}
 
        PONCA_MULTIARCH void clear();
 
        PONCA_MULTIARCH std::pair<typename Self::iterator, bool> insert(const T& _value);
 
        PONCA_MULTIARCH [[nodiscard]] bool contains(T _value) const;
 
    public:
        PONCA_MULTIARCH [[nodiscard]] inline Self::const_iterator cbegin() const;
 
        PONCA_MULTIARCH [[nodiscard]] inline Self::const_iterator cend() const;
 
        PONCA_MULTIARCH [[nodiscard]] inline Self::iterator begin();
 
        PONCA_MULTIARCH [[nodiscard]] inline Self::iterator end();
 
    private:
        container_type m_data{}; //< Where we store the elements in memory
    };
} // namespace Ponca
 
#include "./hashset.hpp"