It seems as though [pit cells](https://github.com/jblindsay/go-spatial/blob/master/tools/breachDepressions.go#L390) and [edge cells](https://github.com/jblindsay/go-spatial/blob/master/tools/breachDepressions.go#L384) should be mutually exclusive. If so, this would permit the elimination of the internal check [here](https://github.com/jblindsay/go-spatial/blob/master/tools/breachDepressions.go#L402) and an early break [here](https://github.com/jblindsay/go-spatial/blob/master/tools/breachDepressions.go#L377).
It seems as though pit cells and edge cells should be mutually exclusive.
If so, this would permit the elimination of the internal check here and an early break here.