Re: [Boost-Users] Re: [boost] Iterator Adaptor Poll

At 11:10 AM 7/26/2002, David Abrahams wrote:

OK, here's my (untested) singly-linked-list iterator:

Yes! Nice! Having this would have saved me a lot of bumbling around. How about supplying slist_node with an operator++ (and eliminating slist_policies::increment), so that you are illustrating the two different possibilities for supplying a required operation. That was something that confused me initially. Another thing that still confuses me is why you need to specify Value, but can let Reference, Pointer, and Distance default. A little cometary in the docs which go with the example to explain the rationale for your choice of template parameter values would be much appreciated. --Beman

typedef std::string slist_data; struct slist_node { slist_node* next; slist_data data; };

struct slist_policies : default_iterator_policies { template <class IteratorAdaptor> void increment(IteratorAdaptor& x) { x.base() = x.base()->next; }

template <class IteratorAdaptor> typename IteratorAdaptor::reference dereference(IteratorAdaptor& x) { return x.base()->data; }

// initialize, equal covered by default policies };

typedef iterator_adaptorstd::forward_iterator_tag > slist_iterator;

typedef iterator_adaptorstd::forward_iterator_tag > slist_const_iterator;