Observers have lots of interfaces, depending on how they are called (e.g., with/without xdot/xdotdot, with Vector's vs a MultiVector, etc). Rather than having lots of XYZimpl functions, try to make all the interfaces call a single impl function. This makes modifications of actual implementation easier, since we only have to mod one fcn.
As a side note: I think I would remove all the MultiVector interfaces in the discretization: as I did in one of the observers, the interface that takes a MultiVector (consisting of x, possibly xdot, possibly xdotdot) can simply extract the MV columns, and call the proper interface with Vector's. This would reduce the amount of interfaces we need to implement in our classes. But that's just a wishlist thought.
Observers have lots of interfaces, depending on how they are called (e.g., with/without xdot/xdotdot, with Vector's vs a MultiVector, etc). Rather than having lots of XYZimpl functions, try to make all the interfaces call a single impl function. This makes modifications of actual implementation easier, since we only have to mod one fcn.
As a side note: I think I would remove all the MultiVector interfaces in the discretization: as I did in one of the observers, the interface that takes a MultiVector (consisting of x, possibly xdot, possibly xdotdot) can simply extract the MV columns, and call the proper interface with Vector's. This would reduce the amount of interfaces we need to implement in our classes. But that's just a wishlist thought.