hash.hpp

 
#pragma once
 
namespace toast {
 
inline constexpr uint64_t k_golden_gamma = 0x9e3779b97f4a7c15ull;
 
[[nodiscard]]
constexpr auto splitmix64(uint64_t value) noexcept -> uint64_t {
  value = (value ^ (value >> 30)) * 0xbf58476d1ce4e5b9ull;
  value = (value ^ (value >> 27)) * 0x94d049bb133111ebull;
  return value ^ (value >> 31);
}
 
constexpr void hashCombine(uint64_t& seed, uint64_t value) noexcept {
  seed = splitmix64(value + k_golden_gamma + seed);
}
 
constexpr void hashFloats(uint64_t& seed, const float* data, size_t count) noexcept {
  for (size_t i = 0; i < count; ++i) {
    hashCombine(seed, std::bit_cast<uint32_t>(data[i]));
  }
}
 
}