Is this the only way to implement the << operator or not?

Suppose that you have the following code:

#include <iostream>

template <typename T>
class Example
{
    public:
        Example() { };
        Example(const T &_first_ele, const T &_second_ele) : first_(_first_ele), 
        second_(_second_ele) { }

        friend std::ostream &operator<<(std::ostream &os, const Example &a)
        {
            return (os << a.first_ << " " << a.second_);
        }

    private:
        T first_;
        T second_;
};

int main()
{
    Example example_(3.45, 24.6);
    std::cout << example_ << "\n";
    return 0;
}

Is this the only way to overload the << operator?

    friend std::ostream &operator<<(std::ostream &os, const Example &a)
    {
        return (os << a.first_ << " " << a.second_);
    }

In terms of performance, is it the best way to overload it or are there better options to do this implementation?