Make value-initialized iterators of intrusive containers comparable

[fdegros@…]

Can value-initialized iterators of intrusive containers be compared?

For example, is the following code valid and well-defined?

using MyList = boost::intrusive::list<MyNode>;
using It = MyList::iterator;

It a = It();
It b = It();

assert(a == b);

This property is useful when it comes to returning empty ranges without having to create a dummy empty container.

If intrusive containers already support this property, then it would be good to explicitly mention it in the documentation. If not, I would like to add it as a feature request.

[Ion Gaztañaga]

Thanks for the ticket. Boost.Intrusive supports comparison of value-initialized iterators. Documentation was missing, so I've done the following commit:

​https://github.com/boostorg/intrusive/commit/47c8a19cfded4e31d03cd758a8663389d837b8be

[fdegros@…]

Excellent.