This is distinct from the physical view represented by the Class Diagrams available in all SKUs of Visual Studio ... Preprocessed text templates use a different custom tool, which creates and compiles ...

and have be tired of paste code or hope a better intuitive expression, check out and try it; The way use it, just click context menu item from a selected Class file node in Visual Studio Solution ...

To export a class diagram that you created from code in a project, save the diagram as an image ... export the diagram again in Visual Studio.