Hi I have a code like this, I think both the friend overloaded operator and conversion operator have the similar function. However, why does the friend overloaded operator is called in this case? What's the rules?

Thanks so much!

class A{

    double i;
public:
    A(int i):i(i) {}
    operator double () const { cout<<"conversion operator"<<endl;return i;}                            // a conversion operator
    friend bool operator>(int i, A  a);                            // a friend funcion of operator >
};

bool operator>(int i, A  a ){
    cout<<"Friend"<<endl;
    return i>a.i;
}
int main()
{
    A  aa(1);
     if (0 > aa){
         return 1;
      }
}