Feature request: WARN_IF_UNDOC_FUNC

[maxwai]

I'd like to request an additional configuration parameter named WARN_IF_UNDOC_FUNC or similar.

This parameter would be similar to WARN_IF_UNDOCUMENTED but would only generate warnings on undocumented functions and not members in general.

We would need this in our current project at work, where it is required that functions are documented but variables are very often fine to be left empty.