Signed to unsigned conversions can happen and can cause unexpected results. For example:
int s = -3; unsigned int u = s;
The unsigned short variable will be assigned with a value of 0xfffffffd, that is, the two's compliment of 3. This may be the result you want, but it is an odd way of getting it.
Interestingly, if you try and compare these two variables, the compiler will issue a warning:
if (u < s) // C4018 cout << "u is smaller than s" << endl;
The Visual C++ warning C4018 given here is '<': signed/unsigned mismatch, which says that you cannot compare a signed and unsigned type, and to do so would need a cast.
