Kernel/include_std/std/functional.hpp

51 lines
1.6 KiB
C++

/*
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/>.
*/
#ifndef __FENNIX_KERNEL_STD_FUNCTIONAL_H__
#define __FENNIX_KERNEL_STD_FUNCTIONAL_H__
#include <types.h>
#include <assert.h>
namespace std
{
template <typename Key>
struct hash
{
size_t operator()(const Key &key) const
{
static_assert(sizeof(size_t) == sizeof(uint64_t)); // size_t and uint64_t must have the same size
const uint64_t fnv_offset_basis = 14695981039346656037ull;
const uint64_t fnv_prime = 1099511628211ull;
const uint8_t *data = reinterpret_cast<const uint8_t *>(&key);
const size_t size = sizeof(Key);
uint64_t ret = fnv_offset_basis;
for (size_t i = 0; i < size; ++i)
{
ret ^= static_cast<uint64_t>(data[i]);
ret *= fnv_prime;
}
return static_cast<size_t>(ret);
}
};
}
#endif // !__FENNIX_KERNEL_STD_FUNCTIONAL_H__