D1780: smartset: split generatorset classes to avoid cycle

[yuja (Yuya Nishihara)]

yuja accepted this revision.
yuja added a comment.
This revision is now accepted and ready to land.


  Queued, thanks. I've made asc/desc classes private as their constructor
  behavior is weird.
  
  > @staticmethod could be a simpler way to break cycles.
  
  Subclassing is a better tool in this case since we want to override `__contains__`,
  which can't be replaced by `__dict__['__contains__']`.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D1780

To: indygreg, #hg-reviewers, quark, yuja
Cc: yuja, quark, mercurial-devel