Represents one of the group/accumulator operators,
for the $group
aggregation.
The $stdDevPop group accumulator (since MongoDB 3.
The $stdDevPop for a single field (since MongoDB 3.
The $stdDevSamp group accumulator (since MongoDB 3.
The $stdDevSamp for a single field (since MongoDB 3.
(Since version 0.12.0) Use SumAll
Factory to declare custom call to a group function.
Sum operation of the form $sum: 1
(groupAggregation: StringAdd).self
(groupAggregation: StringFormat).self
(groupAggregation: ArrowAssoc[GroupAggregation[P]]).x
(Since version 2.10.0) Use leftOfArrow
instead
(groupAggregation: Ensuring[GroupAggregation[P]]).x
(Since version 2.10.0) Use resultOfEnsuring
instead