Quote: "giving me compiler errors, saying it expects a semicolon at the end of the signatures (implementations, not declarations) for my class methods in the .mm file"
If you click on the file and check the far right pane (you may have to click the button in the top right to show this pane) it will have a source type field. This should read Objective C++ source, otherwise it will complain about objective C. You can mark any file extension as objective C, we do this with .cpp files so they will compile when including objective C files.