Peter Dimov saved me from a collosal blunder by correcting my impression that shared_ptr wasn't thread-safe. I've posted a revised draft here: http://www.goingware.com/tips/smart-pointers-and-automated-testing/#thread-s... I hadn't previously understood that thread-safety is not an all or nothing proposition, that is, that one can only guarantee that certain kinds of simultaneous operations will work. My revised text points that out and quotes the first paragraph of shared_ptr's doc on thread safety. I *did* know that there are different degrees of exception safety, so I compare thread-safety guarantees to that. When I cover exception safety in a week or so I'll discuss what that means; sometimes for reasons of performance or memory conservation, one must choose not to be completely exception-safe. Sermon at the Soup Kitchen http://www.goingware.com/tips/smart-pointers-and-automated-testing/ It's going to be about three hours before I post the final section and submit to Kuro5hin. My first try at "The Right Tool for the Job" in my Kuro5hin diary was characterized by one K5 member as "Utterly incomprehensible", and I realize now he's absolutely correct, so I need to address that. I'm going to add a small section to it that I think I'll call "Every Engineer's Solemn Duty" that exhorts the reader to do the right thing when his company plows ahead with a disastrous engineering decision, even if one risks losing one's job, getting blacklisted, sued or even imprisoned. I don't think most engineers ever spend much time thinking about such things until they are suddenly faced with actually making the awful decision to issue an ultimatum, as I did, or blow the whistle, as I still might. I'm lucky I only lost my job. Think of the poor Morton Thiokol engineer who didn't trust his conscience when he knew the Space Shuttle's O-rings had frozen. He settled for reporting the risk of explosion through company channels, and trusted that Morton Thiokol would do the right thing. By not raising Hell and going directly to NASA when he realized the launch hadn't been canceled, he allowed seven people to lose their lives, a billion dollar spacecraft to be destroyed, and the US space program to be set back several years. If I can find a good web page about it, I'm also going to mention the Ford Pinto's exploding gas tank. It came out in a lawsuit that Ford's engineers made a calculated decision to let the gas tank go ahead and explode because they didn't think the cost of paying the inevitable lawsuit damages would be as much as the added manufacturing costs of a safer tank. Before quitting it to run "Yoyodyne" full time, "Jack's" last job was managing a team designing a novel, experimental new medical device, the failure of which would doom the patient to certain death within minutes. I might send a link to "Sermon at the Soup Kitchen" to his ex-employer, along with an explanation of just who Jack and Yoyodyne really are. And yes, I'm well aware that if Jack ever reads my sermons he might try to drag me into court. At least I can sleep soundly at night. You should see all the emails I *don't* post online. Yours, -- Michael D. Crawford