Bit shift
Defects in bit-shift operations, where the shift is incorrect for the operand it is applied to. The common faults are a shift count that meets or exceeds the type’s width — which is undefined on many platforms — and shifting a signed value so that bits move into or out of the sign position, changing the value’s meaning rather than just its magnitude.
Because the operators accept any count and any operand type, the mistake compiles cleanly and yields a platform-dependent or sign-corrupted result.