[Boost-users] "smart list" container?

Hello, I have run into a situation where the following std::list-like container would be useful. - The container itself would act more or less identically to std::list; - The iterators on the container would act like boost::weak_ptr in that they would know that they are invalid when the list element that they point to is removed. Does anyone know of such a container in any of the boost libraries, in another library or a way to accomplish the task using other means (such as iterator adaptors)? I looked at the newly proposed "smart containers" library, but it seems to be solving a different problem despite the similarity with the name I am using to describe what I want. Thanks in advance, David M. Jones