Application domains and Visual C++
If you have a __clrcall virtual function, the vtable will be per application domain (appdomain). If you create an object in one appdomain, you can only call the virtual function from within that appdomain. In mixed mode (/clr) you will have per-process vtables if your type has no __clrcall virtual functions. The /clr:pure and /clr:safe compiler options are deprecated in Visual Studio 2015 and unsupported in Visual Studio 2017.
For more information, see: