Re: featurep

[Richard Stallman]

    I didn't include all the standard features, so while
      (featurep 'make-network-process '(:family local))
    returns t iff local sockets are supported, testing with
      (featurep 'make-network-process '(:family nil))
    returns nil, because the default is always supported, so there
    is no reason to (be able to) test for it.  Is that ok?

That seems reasonable.

    BTW, I've changed Ffeaturep to use Fmember instead of Fmemq to compare
    features, so we can now use all sorts of data (e.g. lists or strings)
    as subfeatures.

Yes, that was essential here.