Provide a way to specify a default disposer

[fdegros@…]

It would be convenient if there was a way to specify a default disposer to be applied to elements stored in an intrusive container. This would make it easier to write containers that take ownership of their inserted elements.

This would impact the container's destructor as well as the methods erase, erase_after, clear, remove, remove_if, pop_front, pop_back, assign, unique and clone_from.

The library should probably provide a no-op disposer, which would be the default one used by intrusive containers. Particular care should be taken in clear and containers' destructors in order to avoid calling the no-op disposer for every element.

For example:

boost::intrusive::list<MyElement, boost::intrusive::disposer<std::default_delete<MyElement>>> elems;
elems.insert(*new MyElement);

// Clearing the collection deletes the elements.
elems.clear();

[fdegros@…]

Ping? Any idea or progress on this topic?

[Ion Gaztañaga]

Configuring the deleter would require also a cloner for some functions. Maybe a wrapper class that manages memory could be helpful, but I have no clear idea on what's the best approach.

[fdegros@…]

Where would a cloner be required if we had a default deleter?