This has the (desired) side effect of making containers covariant over
their input type, so we also add some assertions to ensure that this
doesn't regress.
It's great to see activity here again! I've been maintaining a fork because of certain fixes I needed, but if that's ok with you I'll work on gradually merging those fixes back in here.
This has the (desired) side effect of making containers covariant over their input type, so we also add some assertions to ensure that this doesn't regress.
Fixes #196.