Errors trying to overload template class friend << operator

Question

Trying to code a better version of array type i have run into an issue. For some reason the declaration doesnt work. It throws at me bunch of weird errors. Tried looking up the issue but havent found anything so far. Here is the code:

Template <class T>
class SafeArray {

private:
    int size;
    int elements;
    int index;
    T* arr;

public:

    SafeArray(int n);
    ~SafeArray();
    void push_back(T item);
    void resize(int size);
    friend std::ostream& operator << (std::ostream& os, const SafeArray<T>& ar)


};

And the implementation outside the class:

template<class T>
std::ostream& operator << <T> (std::ostream& os, const SafeArray<T> & arr) {

    for (int i = 0; i < arr.elements; i++) {
        std::cout << arr[i] << " ";
    }

    std::cout << std::endl;

    return os;
}

Answer 1

If you want friend template , the friend declaration should be

template <class T>
class SafeArray {
    ...
    template<class X>
    friend std::ostream& operator << (std::ostream& os, const SafeArray<X>& ar);
};

the implementation should be

template<class T>
std::ostream& operator << (std::ostream& os, const SafeArray<T> & arr) {
    ...
}

LIVE

BTW: In the implementation of operator<< , I think std::cout << arr[i] << " "; should be std::cout << arr.arr[i] << " "; .