Function SafeLeftShift

cpp/src/arrow/util/int_util_overflow.h:232–235

/// Signed left shift with well-defined behaviour on negative numbers or overflow
template <typename SignedInt, typename Shift>
SignedInt SafeLeftShift(SignedInt u, Shift shift) {
  using UnsignedInt = typename std::make_unsigned<SignedInt>::type;
  return static_cast<SignedInt>(static_cast<UnsignedInt>(u) << shift);
}

}  // namespace internal
}  // namespace arrow