This (development) question (from a user's point of view) has been bugging me. This may not be the right list, but I haven't found one yet. Now that gnu classpath and openjdk are merging, and gcj is being used to initially compile openjdk, how about using the gcj cni idea for native access to c++? In fact, why can't we have a cni-subset of c++ as a frontend for compiling to byte code? This was (deliberately) not done before, even though all the needed capability had been there. But why not explore that now? (Not a compiler writer myself.) The binding from a cni-subset into full c++ would be easier than jni or jna, especially if the c++ code has good separation between interface and implementation.

I am using swig (a great program) right now to write a java binding for a c++ library. c++ is flattened to c on the native side, and then rebuilt back into objects on the java side. Seems like much ado about very little difference.