I used SWIG once a long time ago, for a project that did actually target multiple languages.

I got burned so bad that I ditched all efforts at automatic binding generations from there on out. Debugging this thing was impossible (to me, a long long time ago) and I ended up writing manual bindings to python & matlab instead. Those two were the important targets anyhow, and it allowed me to really think through how I exposed & handed over the different chunks of memory being allocated in the native code.