Question

I have created a C++ implementation of a collection type.
I would like to add iteration support so that developers may use the “for each” statement on it.
How can I do that?

Answer 1

The standard idiom is : expose types iterator and const_iterator and provide minimum two functions namely, begin() and end() as:

template</*.....*/>
class Collection
{
 public:
     typedef /*...*/ iterator;
     typedef /*...*/ const_iterator;

     iterator begin();
     iterator end();

     const_iterator begin() const;
     const_iterator end() const;
};

Once you implement these, your collection can be used in std::for_each, and in a lot other algorithmic functions which are defined in <algorithm>.