This module defines facilities for efficient checking of integral operations against overflow, casting with loss of precision, unexpected change of sign, etc. The checking (and possibly correction) can be done at operation level, for example opChecked!"+"(x, y, overflow) adds two integrals x and y and sets overflow to true if an overflow occurred. The flag overflow (a bool passed by reference) is not touched if the operation succeeded, so the same flag can be reused for a sequence of operations and tested at the end.