[niekb]

That was mostly meant as irony/a joke, but I admit that's not really clear from the text... For the sake of clarity, if you need thread-safety, probably best to just use std::shared_ptr / std::weak_ptr.

[Kranar]

It's a common misconception that std::shared_ptr is thread safe. The counter is thread safe, but the actual shared_ptr itself can not be shared across multiple threads.

There is now atomic_shared_ptr which is thread safe.

[delduca]

It is now a template specialization of atomic std::atomic<std::shared_ptr<T>>.