Calling NSWindow methods on window gotten from SDL2

In SDL2, you can get a pointer to an NSWindow by fetching the SDL2 window’s information (seen here: Once I’ve gotten the pointer to the window, I’d like to be able to modify that object’s properties, namely setting titlebarAppearsTransparent to true. However, this doesn’t seem to work and I get the error: error: incomplete definition of type '_NSWindow' when I use the code:

    NSWindow *nsWindow =;
    nsWindow.titlebarAppearsTransparent = true;
    nsWindow.titleVisibility = .Hidden;

Obviously this shouldn’t work because I’m basically dumping Swift code into C++, but I’m not sure how I’m supposed to go about achieving what I want.

Use Objective-C / Objective-C++. AFAIK all of SDL’s Mac/iOS code that can’t be written in C is written in Objective-C.