Fennix/Kernel/include_std/array

/*
	This file is part of Fennix Kernel.

	Fennix Kernel is free software: you can redistribute it and/or
	modify it under the terms of the GNU General Public License as
	published by the Free Software Foundation, either version 3 of
	the License, or (at your option) any later version.

	Fennix Kernel is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	GNU General Public License for more details.

	You should have received a copy of the GNU General Public License
	along with Fennix Kernel. If not, see <https://www.gnu.org/licenses/>.
*/

#pragma once

#include <initializer_list>
#include <cstddef>
#include <iterator>
#include <algorithm>
#include <stdexcept>

namespace std
{
	template <class T, std::size_t N>
	struct array
	{
	public:
		using value_type = T;
		using size_type = std::size_t;
		using difference_type = std::ptrdiff_t;
		using reference = value_type &;
		using const_reference = const value_type &;
		using pointer = value_type *;
		using const_pointer = const value_type *;

		using iterator = value_type *;
		using const_iterator = const value_type *;
		// using reverse_iterator = std::reverse_iterator<iterator>;
		// using const_reverse_iterator = std::reverse_iterator<const_iterator>;

	private:
		value_type ptr[N]{};

	public:
		constexpr array() = default;

		constexpr array(std::initializer_list<T> list)
		{
			if (list.size() != N)
				throw std::length_error("array initializer_list size mismatch");
			std::copy(list.begin(), list.end(), ptr);
		}

		constexpr reference at(size_type pos)
		{
			if (pos >= size())
				throw std::out_of_range("array::at: index out of range");
			return this->operator[](pos);
		}

		constexpr const_reference at(size_type pos) const
		{
			if (pos >= size())
				throw std::out_of_range("array::at: index out of range");
			return this->operator[](pos);
		}

		constexpr reference operator[](size_type pos) { return *(begin() + pos); }
		constexpr const_reference operator[](size_type pos) const { return *(begin() + pos); }
		constexpr reference front() { return *begin(); }
		constexpr const_reference front() const { return *begin(); }
		reference back() { return *(end() - 1); }
		const_reference back() const { return *(end() - 1); }
		constexpr T *data() noexcept { return ptr; }
		constexpr const T *data() const noexcept { return ptr; }
		constexpr iterator begin() noexcept { return ptr; }
		constexpr const_iterator begin() const noexcept { return ptr; }
		constexpr const_iterator cbegin() const noexcept { return ptr; }
		constexpr iterator end() noexcept { return ptr + N; }
		constexpr const_iterator end() const noexcept { return ptr + N; }
		constexpr const_iterator cend() const noexcept { return ptr + N; }
		// constexpr reverse_iterator rbegin() noexcept { return reverse_iterator(end()); }
		// constexpr const_reverse_iterator rbegin() const noexcept { return const_reverse_iterator(end()); }
		// constexpr const_reverse_iterator crbegin() const noexcept { return const_reverse_iterator(end()); }
		// constexpr reverse_iterator rend() noexcept { return reverse_iterator(begin()); }
		// constexpr const_reverse_iterator rend() const noexcept { return const_reverse_iterator(begin()); }
		// constexpr const_reverse_iterator crend() const noexcept { return const_reverse_iterator(begin()); }
		constexpr bool empty() const noexcept { return begin() == end(); }
		constexpr size_type size() const noexcept { return /*std::distance(begin(), end());*/ N; }
		constexpr size_type max_size() const noexcept { return N; }

		constexpr void fill(const T &value)
		{
			for (size_type i = 0; i < N; ++i)
				ptr[i] = value;
		}

		constexpr void swap(array &other) noexcept(std::is_nothrow_swappable_v<T>)
		{
			for (size_type i = 0; i < N; ++i)
			{
				auto tmp = ptr[i];
				ptr[i] = other.ptr[i];
				other.ptr[i] = tmp;
			}
		}
	};
}