Interfaces, generics, and templates work just fine in KM. I’ve used them all, in many projects. (Audio and video streaming drivers have been in C++ since the 20th Century.) Just about the only major missing feature is exceptions, and that rules out STL, which is a shame.
Thx for the discussion, guys! This is my mistake, I saw the km/crt folder and for some reason decided that this is a full-fledged implementation of C standard =(