public static Vector <T> Vector <S, T>(this IPolyrand random, int len, Interval <S>?domain = null)
where S : unmanaged
where T : unmanaged
=> random.Vector <S>(len, domain).Convert <T>();
public static Vector <N, T> Vector <N, S, T>(this IPolyrand random, Interval <S> domain, N n = default)
where T : unmanaged
where S : unmanaged
where N : ITypeNat, new()
=> random.Vector <N, S>(domain).Convert <T>();
