confused by handling of data type

I have a question regarding data types

1. This code
unsigned short num=65535;
cout << num+2 << endl;

outputs 65537 . I expected it to output 1 because of the value
wrapping around itself if you get my meaning. Does the cout
object have an ability to change to a more suitable data type?
Can anybody shed some light?

Thanks!

It gets promoted to an integer to do the addition. If you force it back into an unsigned short, you will get the wrapping effect.

Code:

---

#include <iostream>
using namespace std;

int main() {
        unsigned short num=65535;
        cout << num+2 << endl;

        cout << (unsigned short) (num+ 2) << endl;
        return 0;
}

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