std::shared_ptr<ICell> IntCell::operator +(const IntCell &in) const
{
std::shared_ptr<IntCell> out = std::shared_ptr<IntCell>(new IntCell());
out->setCellAccess(Computed);
if (overflowAdd(this->val, in.val))
return std::shared_ptr<ErrorCell>(new ErrorCell("Add overflow"));
out->val = this->val + in.val;
//todo:add overflow detect and return ErrorCell
return out;
}
// Subtraction
signed long int overflowSubtract(const signed long int& num,
const signed long int& modifier,
const signed long int& minNum,
const signed long int& maxNum) {
// If they gave a negative modifier, then it is like
// 3 - (-3) = 6. It is the same as 3 + 3 = 6, so send it to the
// addition function
if (modifier < 0) {
return overflowAdd(num, abs(modifier), minNum, maxNum);
// Check for integer overflows
} else if (num - modifier > num
// Check if it goes under the min number
|| num - modifier < minNum) {
// It overflowed, so make it the min possible number that doesn't
// overflow
return minNum;
} else {
// It won't overflow, so it is safe to perform the operation
return (num - modifier);
}
}
