Returning associated "_id" value from update functions.

[Palmik]

Hello,
I wanted to ask if there is an inherent reason for not having update functions (like save) return the updated document's value in the "_id" field (or the one automatically created). After looking at the code, it did not seem like an impossible task, but I might have overlooked something. Or perhaps it's deliberate design decision?

[TonyGen]

Hi Petr, update operation in general does require an _id, although it would make sense for Save and Repsert. It could make sense for Replace but Replace can also be given a Modifier instead of a Document. Ie. Replace is the same as Modify except it only modifies the first matching document in collection. Please provide a pull request if you really want this. Cheers, Tony