"Jonathan Turkanis" <technews@kangaroologic.com> wrote in message news:cgal34$l63$1@sea.gmane.org...
Currently there is detail::is_incrementable, which works well if you only need to distinguish between iterators and very different types. For instance, I would guess that very few if any containers are incrementable (I'd be happy to be proved wrong here), so that if you want define a function which behaves differently for container and iterators you can use is_incrementable.
In this case, I need to know whether or not type T is dereferenceable (and more generally, whether or not it's an iterator). I have a small template metaprogram which determines how an instance of type T should be treated. If it's an iterator, I want to dereference it. Otherwise, I don't.
Don't forget pointers. Also these operators can also be defined as non-member functions.
Pointers are fairly easy to handle. I forgot to mention that I provide a partial template specialization for this case: for any type T, 'is_iterator<T *>::value' evaluates to true. You bring up an important point about operators defined as non-member functions. My current implementation doesn't handle this case, but I may yet be able to fix that. :-) Thanks for the feedback, Alex