Hi,
If you want to go with the classic C++ way (a big chain of #ifdefs), you're allowed to do so just ignore the arch/ folder.
This is not explicitly stated in the documentation, maybe its worth adding it, I don't know.
When I first implemented the new library format I've checked its functionality with two example of the Servo library:
-
the first example uses the classic chain of ifdefs:
LibTest/libraries/Servo at master · cmaglie/LibTest · GitHub -
the second uses the arch/* folders way:
LibTest/libraries/Servo2 at master · cmaglie/LibTest · GitHub
Both can be used, I could say that its a matter of taste, personally my favorite is the method 2).
Also note the with the library.properties you can filter the library from being displayed/compiled on architectures that are not supported by the library itself.