I am a new user of boost pointers and was wondering about the thread safety in boost shared and intrusive pointers. After reading some eariler posts and the current documentation, I am little confused. As per current documentation shared pointers thread safety in shared pointers is on the lines of STL and thus they are not thread safe for writing. But I am pretty sure I read in one of the posts that shared pointer is thread safe for all operations. Also, looking at the operator= and swap, it seems there could be some thread safety issues. Also, I have my own counted_base which I use in intrusive pointer. If my understanding is correct, to ensure thread safety, if I ensure add_ref and release_ref operations are atomic, I am pretty much covering all the bases. Thanks, Pete