Below this code makes many warning in the compiler.

#include 
using namespace std;
int main(int a)
{
cout << a << "\n";
    return 0;
}
int main(char *a)
{
    cout << a << endl;
    return 0;
}
int main(int a, int b)
{
    cout << a << " " << b;
    return 0;
}
int main()
{
    main(3);
    main("C++");
    main(9, 6);
    return 0;
}
But if I use the class in code it will be warning and error free. I can overload the main function shows in bellow code. So, main() function is not reserve function in C++,

#include 
using namespace std;
class Test
{
public:
int main(int s)
{
cout << s << "\n";
        return 0;
    }
    int main(char *s)
    {
        cout << s << endl;
        return 0;
    }
    int main(int s ,int m)
    {
        cout << s << " " << m;
        return 0;
    }
};
int main()
{
    Test obj;
    obj.main(100);
    obj.main("I like C and C++ programming");
    obj.main(100, 200);
    return 0;
}
Output: 100 I like C a 100 200 NB: When i post the code in the blog a unwanted html break "<br />" is displayed in some line, please remove the break to run the code properly