[Numpy-discussion] Deprecate boolean math operators?

[Sebastian Berg]

Hey,

there was a discussion that for numpy booleans math operators +,-,* (and
the unary -), while defined, are not very helpful. I have set up a quick
PR with start (needs some fixes inside numpy still):

https://github.com/numpy/numpy/pull/4105

The idea is to deprecate these, since the binary operators |,^,| (and
the unary ~ even if it is weird) behave identical. This would not affect
sums of boolean arrays. For the moment I saw one "annoying" change in
numpy, and that is `abs(x - y)` being used for allclose and working
nicely currently.

- Sebastian