How is Non-Virtual Interface pattern imlemented in C++?

Question

I am curious about both, a h single and multi-threaded implementation.

Thanks

Answer 1

Here you go...

Google, isn't it amazing? :P

Answer 2

If you have a copy of Effective C++ (3rd Edition) sitting around, Scott Meyers gives a nice treatment of the NVI idiom in Item 35 (page 170).

Answer 3

class base
{
public:
    void bar()
    {
        getReady();
        barImpl();
        cleanup();
    }
    void getReady() {cout << "Getting ready. ";}
    void cleanup()  {cout << "Cleaning up.\n";}
protected:
    virtual void barImpl() {cout << "base::barImpl. ";}
}

class derived : public base
{
protected:
    virtual void barImpl() {cout << "derived::barImpl. ";}
}

int main()
{
    base b;
    derived d;
    b.bar();
    d.bar();
}

Output:

Getting ready. base::barImpl. Cleaning up.
Getting ready. derived::barImpl. Cleaning up.

Answer 4

Your question is vague, but it sounds like you want the Curiously recurring template pattern

There are a lot better people than I to explain this on the web it is used a lot in the boost library. check out boost.iterator documentation and code for a good example