COM Smart Pointers Revisited

摘要

After the second coming of COM, otherwise known as the Windows Runtime, the need for an efficient and reliable smart pointer for COM interfaces is more important than ever. But what makes for a good COM smart pointer? The ATL CComPtr class template has been the de facto COM smart pointer for what feels like decades. The Windows SDK for Windows 8 introduced the ComPtr class template as part of the Windows Runtime C++ Template Library (WRL), which some hailed as a modern replacement for the ATL CComPtr. At first, I also thought this was a good step forward, but after a lot of experience using the WRL ComPtr, I've come to the conclusion it should be avoided. Why? Keep reading.