What are potential dangers when using boost::shared_ptr?

Question

What are some ways you can shoot yourself in the foot when using boost::shared_ptr? In other words, what pitfalls do I have to avoid when I use boost::shared_ptr?

Answer 1

Not precisely a footgun, but certainly a source of frustration until you wrap your head around how to do it the C++0x way: most of the predicates you know and love from don't play nicely with shared_ptr. Happily, std::tr1::mem_fn works with objects, pointers and shared_ptrs, replacing std::mem_fun, but if you want to use std::negate, std::not1, std::plus or any of those old friends with shared_ptr, be prepared to get cozy with std::tr1::bind and probably argument placeholders as well. In practice this is actually a lot more generic, since now you basically end up using bind for every function object adaptor, but it does take some getting used to if you're already familiar with the STL's convenience functions.

This DDJ article touches on the subject, with lots of example code. I also blogged about it a few years ago when I first had to figure out how to do it.