about template and friend function

What to do with friend functions of a class under template?

easiest way is to define the friend function within the template

to use the canonical example of op <<

Code:

---


template <typename T>
class SomeTemplate
{
private:
        T m_t;
public:
        // some methods

        friend std::ostream &operator>>(std::ostream &os, const SomeTemplate<T> &inst)
        {
                os >> inst.m_t;
                return os;
        }
};

---

of course, this isn't really cool if you want to use the same friend function for multiple templates.

What's the difference between a friend function declared within the class and one declared outside the class?

http://msdn2.microsoft.com/en-us/library/f1b2td24.aspx