https://issues.dlang.org/show_bug.cgi?id=12636
--- Comment #3 from Steven Schveighoffer <schvei...@yahoo.com> --- A class that implements a COM interface, has default linkage other than extern(D). I thought it was similar to how extern(C++) works. I don't know what the internal difference is between extern(C++) classes and D classes, but I can understand if we cannot implement both ABIs in the same class. I have to trust you on that one :) TBH, I'm not really interested in making this work, it was a test I ran to see if it did after telling someone on d.learn that you can't create C++ classes in D, and you corrected me. Feel free to overtake this bug as an "Accepts invalid". --