That particular class doesn’t depend on the COM-related pieces of the ATL library. It can be used in any C++ project which targets windows desktop platform. I think since VS2015 ATL is available even in the freeware community edition of the IDE. Before that, it required a commercial edition.

About non-Unicode WinAPI functions, I don’t use them at all in the software I’m developing, nor the TCHAR conditional typedef. VC++ compiler defines wchar_t as a built-in type for the UTF16 strings used in WinAPI functions.

> It can be used in any C++ project which targets windows desktop platform.

Any project which only targets Windows, or at least it can only be used in Windows-specific code. Even if you currently only target Windows, baking platform-specific types into your core is foolish.