How to define operator== for a nasting class of templated-class?

How can I define operator== for a nasting class?

I adds the following code for explain what I mean:

template<class T>
class TemplateClass {
    int val;
public:
    TemplateClass(int val) :
            val(val) {
    }
    TemplateClass(const TemplateClass& tc) = default;
    TemplateClass& operator=(const TemplateClass& tc) = default;

    class Ele {
        int x;
    public:
        Ele(int x) :
                x(x) {
        }
        template<class S>
        friend bool operator==(const Ele& e1, const Ele& e2);
    };
};

template<class T>
bool operator==(const TemplateClass<T>::Ele& e1,
        const TemplateClass<T>::Ele& e2) {
    return e1.x == e2.x;
}  

But it's not working, I get the following error:

'bool operator!=(int)' must have an argument of class or enumerated type

I will be happy to understand how can I fix it.