Generic iterator

Question

I am trying to find a generic way of accessing a set of containers. I have a standard vector and list in addition to another custom list.

The custom list defines an iterator;

class Iterator: public std::iterator<std::forward_iterator_tag, T> {     // ... }  Iterator begin() {     return (Iterator(root)); }  Iterator end() {     return (Iterator(NULL)); } 

with the appropriate operators overloaded.

Ideally, I would like to do this;

class Foo { public:     Foo() {         std::list<int> x;         std::vector<int> y;         custom_list<int> z;          iter = x.begin(); // OR         iter = y.begin(); // OR         iter = z.begin();          // ...     }; private:     std::iterator<int> iter; }; 

But obviously these are all iterators of different types. I can assume all the containers are of the same type however.

Is there an elegant way to solve this problem?

Answer 1

Here are some articles you might find of interest

Giving STL Iterators a Base Class

Type Erasure for C++ Iterators

any_iterator Class Reference

Answer 2

Better late than never...

The latest issue of C-Vu turned up and guess what was in it: That's right, iterators that do exactly what you wanted.

Unfortunately you need to become a member of the ACCU to view the magazine (the article references the Overload article from 2000 that David links to). But for a measly price a year you get a nice magazine to read, conferences and user groups. When you become a member you can view PDF's of the back issues so what are you waiting for?