Calculating Sums in C++

Question

I am not quite grasping calling voids in C++ and could use some help (without the “voids” in the example, the solution is correct):

#include <iostream>
#include <string>
using namespace std;

//complete the function
void int add(int x, int y) {
return x+y;
}

//overload it to sum doubles
void double add(double x, double y) {
return x+y;
}

int main() {

//calling
cout<<add(5,6)<<endl;
cout<<add(1.2, 6.5);

return 0;
}

Answer 1

Void means it will return nothing.
You can't name a function "void int" or "void double". A function in C++ must have only one return type.

Answer 2

How could it be void and int in the same time ?!!
You must declare the function either void or int/ double/ float .... Etc