if len(b) > 0 {
			v.Base = &b[0]
		} else {
			v.Base = (*byte)(unsafe.Pointer(&_zero))
		}
		vecs = append(vecs, v)
	}
	return vecs
}

// offs2lohi splits offs into its low and high order bits.
func offs2lohi(offs int64) (lo, hi uintptr) {
	const longBits = SizeofLong * 8
	return uintptr(offs), uintptr(uint64(offs) >> (longBits - 1) >> 1) // two shifts to avoid false positive in vet
}