Core utilities
Core utility library by Ross Smith
#include "rs-core/hash.hpp"
namespace RS;
template <typename T> concept Hashable;
template <typename T> concept RegularHashable
= Hashable<T> && std::regular<T>;
Hashable matches any type for which a valid specialization of std::hash
exists.
constexpr std::size_t hash_mix() noexcept { return 0; }
constexpr std::size_t hash_mix(std::size_t x) noexcept { return x; }
constexpr std::size_t hash_mix(std::size_t x, std::size_t y) noexcept;
template <std::convertible_to<std::size_t>... TS>
constexpr std::size_t hash_mix(std::size_t x, std::size_t y,
TS... ts) noexcept;
template <std::ranges::range Range>
requires (std::convertible_to<[range value], std::size_t>)
std::size_t hash_mix(const Range& range, std::size_t init = 0);
Hash mixing functions, for an arbitrary number of input hash values supplied either as an explicit list or a range.
constexpr std::uint32_t kernighan_hash(const void* ptr,
std::size_t len) noexcept;
An implementation of Brian Kernighan’s simple general purpose hash function.
class SipHash {
SipHash() noexcept;
explicit SipHash(std::uint64_t key0, std::uint64_t key1) noexcept;
explicit SipHash(const void* key) noexcept;
SipHash(const SipHash& sh) noexcept;
SipHash(SipHash&& sh) noexcept;
~SipHash() noexcept;
SipHash& operator=(const SipHash& sh) noexcept;
SipHash& operator=(SipHash&& sh) noexcept;
std::uint64_t operator()(const void* ptr, std::size_t len) const noexcept;
std::uint64_t operator()(std::string_view view) const noexcept;
};
SipHash-2-4-64 by Jean-Philippe Aumasson and Daniel J Bernstein.
The key can be supplied either as a pair of 64-bit integers or as raw bytes. The default constructor uses a key consisting of ascending bytes. If the third constructor is used, the key pointer must point to an array of at least 16 bytes.