Generate hash code

HashCode.cs

public readonly struct HashCode
{
    private readonly int _value;

    private HashCode(int value) => _value = value;

    public static HashCode Seed { get; } = new HashCode(17);

    public HashCode Combine<T>(T obj)
    {
        var h = EqualityComparer<T>.Default.GetHashCode(obj);
        return unchecked(new HashCode((_value * 31) + h));
    }

    public override int GetHashCode() => _value;

    public static implicit operator int(HashCode hash) => hash._value;
}

Person.cs

public class Person
{
    public string FirstName { get; set;}

    public string LastName { get; set; }

    public override int GetHashCode()
    {
        return HashCode.Seed
            .Combine(FirstName)
            .Combine(LastName)
            .GetHashCode();
    }
}