In C++, which of the following is required for overloading the function operator? code example

Example 1: Operator overloading in C++ Programming

#include <iostream>
using namespace std;

class Test
{
   private:
      int count;

   public:
       Test(): count(5){}

       void operator ++() 
       { 
          count = count+1; 
       }
       void Display() { cout<<"Count: "<<count; }
};

int main()
{
    Test t;
    // this calls "function void operator ++()" function
    ++t;    
    t.Display();
    return 0;
}

Example 2: operator overloading in c++

Box operator+(const Box&);