     case 65...127:
         let upperBits = lhs.value.lowerBits << UInt64(rhs - 64)
         return UInt128(upperBits: upperBits, lowerBits: 0)
-    default: return UInt128(0)
+    default: return 0
     }
 }
 public func <<=(lhs: inout UInt128, rhs: UInt128) {

/// Shifts `lhs`' bits left by `rhs` bits and returns the result.
public func <<(lhs: UInt128, rhs: UInt128) -> UInt128 {
    if rhs.value.upperBits > 0 || rhs.value.lowerBits > 128 {
        return UInt128(0)
    }
    switch rhs {
    case 0: return lhs // Do nothing shift.

/// Shifts `lhs`' bits right by `rhs` bits and returns the result.
public func >>(lhs: UInt128, rhs: UInt128) -> UInt128 {
    if rhs.value.upperBits > 0 || rhs.value.lowerBits > 128 {
        return 0
    }
    switch rhs {
    case 0: return lhs // Do nothing shift.
