Jon Hanna
ed99856139
With Null and Undefined BsonValue's, one such value is indistinguishable from another, so singletons can be used for them, reducing allocations. With BsonValue containing booleans as well as there being only so there's a similar advantage with the extra benefit that if there is only one true value then a reference-equals check can be used instead of unboxing to determine the value to write.
