Module checked
Source - CheckedAdd
 - Performs addition that returns 
None instead of wrapping around on
overflow. - CheckedDiv
 - Performs division that returns 
None instead of panicking on division by zero and instead of
wrapping around on underflow and overflow. - CheckedMul
 - Performs multiplication that returns 
None instead of wrapping around on underflow or
overflow. - CheckedNeg
 - Performs negation that returns 
None if the result can’t be represented. - CheckedRem
 - Performs an integral remainder that returns 
None instead of panicking on division by zero and
instead of wrapping around on underflow and overflow. - CheckedShl
 - Performs a left shift that returns 
None on shifts larger than
or equal to the type width. - CheckedShr
 - Performs a right shift that returns 
None on shifts larger than
or equal to the type width. - CheckedSub
 - Performs subtraction that returns 
None instead of wrapping around on underflow.