Template function inside template class

Question

I have this code:

template <class T>
class MyClass {
public:
    template <class U>
    void foo() {
        U a;
        a.invoke();
    }
};

I want it in this form:

template <class T>
class MyClass {
public:
    template <class U>
    void foo();
};

template <class T> /* ????? */
void MyClass<T>::foo() {
    U a;
    a.invoke();
}

How can I do this? What is the correct syntax?

Answer 1

Write this:

template <class T>
template <class U>
void MyClass<T>::foo() { /* ... */ }