I had this disagreement with Thorsten in Lillehammer (or was it Oxford?) but he was unimpressed with my arguments. I was wondering what Boost as a whole would think: My Thesis: the library should support copying and assignment of pointer containers using the usual copy/assignment syntax, rather than only allowing a copy via a clone() function. Rationale: Not being able to copy and assign pointer containers is an arbitrary restriction that limits usefulness and expressivity. The argument Thorsten gives against copyability is that the elements would have to be clone()d rather than copied, which is expensive because there's a dynamic allocation per element. I don't get it; we don't arbitrarily prohibit copying of std::vector<std::string> even though that incurs a dynamic allocation per element. Example: Consider std::pair<int,some_pointer_container>. Almost nothing works. IIUC, it's not copyable, can't be initialized, and can't be clone()d. -- Dave Abrahams Boost Consulting www.boost-consulting.com