/*
	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

namespace std
{
	template <typename T>
	struct equal_to
	{
		bool operator()(const T &lhs, const T &rhs) const
		{
			return lhs == rhs;
		}
	};

	template <typename Key>
	struct hash
	{
		size_t operator()(const Key &key) const
		{
#if defined(a64)
			static_assert(sizeof(uintptr_t) == sizeof(uint64_t));
			const uint64_t FNV_OFFSET_BASIS = 14695981039346656037ull;
			const uint64_t FNV_PRIME = 1099511628211ull;
#elif defined(a32)
			static_assert(sizeof(uintptr_t) == sizeof(uint32_t));
			const uint32_t FNV_OFFSET_BASIS = 2166136261u;
			const uint32_t FNV_PRIME = 16777619u;
#else
#error "Unsupported architecture"
#endif

			const uint8_t *data = reinterpret_cast<const uint8_t *>(&key);
			const size_t size = sizeof(Key);
			uintptr_t hash = FNV_OFFSET_BASIS;

			for (size_t i = 0; i < size; ++i)
			{
				hash ^= static_cast<uintptr_t>(data[i]);
				hash *= FNV_PRIME;
			}

			return static_cast<size_t>(hash);
		}
	};
}