Did you recompile the custom layer
after making the change ?
To be clear, the line
validates that the extension matches one of the extensions from the config file, so you still need it in the config file, even after your change.
On my machine, it's working. But the mm file I used contained only C code since I don't' know ObjectiveC. If ObjectiveC syntax is too different from C/C++, the syntax highlighting and other code related features might not work at all (I don't know). There are still ways to have basic syntax highlighting
, but you may have to do it yourself.