* to the unsigned type of the same length.
* 6. Expand x (or the result of step 5) to a Blk,
* and store it in the number array.
* to the unsigned type of the same length.
* 6. Expand x (or the result of step 5) to a Blk,
* and store it in the number array.
// If a is zero, copy b and flip its sign. If b is zero, copy a.
if (a.sign == zero) {
BigUnsigned::operator =(b);
// If a is zero, copy b and flip its sign. If b is zero, copy a.
if (a.sign == zero) {
BigUnsigned::operator =(b);
// If their signs differ, take a.sign and add the magnitudes.
else if (a.sign != b.sign) {
sign = a.sign;
// If their signs differ, take a.sign and add the magnitudes.
else if (a.sign != b.sign) {
sign = a.sign;