[traverse] reverse meaning of isolation in difference#887

Merged

barendgehrels merged 3 commits intoboostorg:developfrom barendgehrels:fix/traverse

Jul 28, 2021

+193-88

Commits on Jul 21, 2021

[traverse] reverse meaning of isolation in difference
barendgehrels
committed
[traverse] avoid using isolated for originally non-isolated regions
barendgehrels
committed
[test] add testcase for issue boostorg#888 polygon 53
barendgehrels
committed