public static Vec128 <T> ToCpuVec <T>(this BitString src, N128 n) where T : unmanaged => src.Pack().As <byte, T>().ToSpan128().ToCpuVec128();
public static BitVector128 BitVector(this IPolyrand random, N128 n) => (random.Next <ulong>(), random.Next <ulong>());
public static BitVector128 ToBitVector(this ulong src, N128 n) => src;
public static BitVector128 ToBitVector(this BitString src, N128 n) => BitVector128.FromBitString(src);
public static BitVector128 ToBitVector(this long src, N128 n) => (ulong)src;
public static BitVector128 ToBitVector(this int src, N128 n) => (uint)src;
public static BitVector128 ToBitVector(this ushort src, N128 n) => src;
public static BitVector128 ToBitVector(this short src, N128 n) => (ushort)src;
public static BitVector128 ToBitVector(this byte src, N128 n) => src;