toInt method
Only safe if the value fits in the hi limb being zero and the lo
limb being double-safe — delegates to Uint64.toInt()'s own guard,
throwing IntegerError otherwise (use toBigInt for the general
case).
Implementation
int toInt() {
if (!_hi.isZero) {
throw IntegerError.toIntConvertionError;
}
return _lo.toInt();
}