UnityECS/LocalPackages/com.nimin.lowlevel/Runtime/LowLevelUtility.cs

using Unity.Collections.LowLevel.Unsafe;

namespace GameCore.LowLevel
{
    public static class LowLevelUtility
    {
        public static int HashCombine(int h1, int h2)
        {
            var hash = h1;
            hash = (hash * 397) ^ h2;
            return hash;
        }

        public static int HashCombine(int h1, int h2, int h3)
        {
            return HashCombine(HashCombine(h1, h2), h3);
        }

        public static int OffsetOf<T, F>()
        {
            var fields = typeof(T).GetFields();
            foreach (var f in fields)
            {
                if (f.DeclaringType == typeof(F))
                    return UnsafeUtility.GetFieldOffset(f);
            }

            return -1;
        }
    }
}