Question

I had obtained this error while overloading the >> operator, and I have no idea why.

istream& operator>>(istream& stream, unsigned int in)
{
    stream >> in;
    //manyoperators
    if(in>10)
       in = -1;
    return stream;
}

Part of code with error:

unsigned int tmm;
    cin >> tmm;

Why? I have no other overloading of >>.
What it may be?

Answer 1

You can overload functions(in your case operator >>) for only custom classes not inbuilt data types.
The C++ standard library itself provides overloads for inbuilt data types.