diff options
Diffstat (limited to 'src/util/hash.tpp')
-rw-r--r-- | src/util/hash.tpp | 22 |
1 files changed, 22 insertions, 0 deletions
diff --git a/src/util/hash.tpp b/src/util/hash.tpp new file mode 100644 index 0000000..146cfa0 --- /dev/null +++ b/src/util/hash.tpp @@ -0,0 +1,22 @@ +#pragma once + +#include "hash.hpp" + +#include <cstdint> +#include <functional> + +/** + * Combines the hash 'seed' with the hash of 'value'. + * + * @param seed A hash that will be mutated + * @param value A hashable value + */ +template <typename Value> +void hash_combine(std::size_t &seed, const Value &value) noexcept +{ + constexpr uint32_t shift_left = 6; + constexpr uint32_t shift_right = 2; + + seed ^= std::hash<Value>()(value) + GOLDEN_RATIO + (seed << shift_left) + + (seed >> shift_right); +} |