Why does the most negative int value cause an error about ambiguous function overloads?

Question

I\'m learning about function overloading in C++ and came across this:

void display(int a)
{
    cout << \"int\" << endl;
}

void display(unsigned         


        

Answer 1

The expression -2147483648 is actually applying the - operator to the constant 2147483648. On your platform, int can't store 2147483648, it must be represented by a larger type. Therefore, the expression -2147483648 is not deduced to be signed int but a larger signed type, signed long int.

Since you do not provide an overload for long the compiler is forced to choose between two overloads that are both equally valid. Your compiler should issue a compiler error about ambiguous overloads.