Thread safety of the reference count of a C++/CX WinRT pointer

Question

I was under the impression that the reference count to WinRT objects was thread safe, given the use case. But I\'ve run into a bug that I don\'t know any other way to explain. F

Answer 1

Changes to the reference count of a ref class object are synchronized, but changes to a T^ object are not.

You have two threads accessing _latest at the same time, and one of those threads is modifying _latest, so you need to synchronize access to _latest, e.g. using a std::mutex.