Returns a BSON writer that returns the result of applying f
on the BSON value from this writer.
Returns a BSON writer that returns the result of applying f
on the BSON value from this writer.
the function to apply
Tries to produce a BSON value from an instance of T, returns None if an error occurred.
Tries to produce a BSON value from an instance of T.
A writer that produces a subtype of BSONValue fron an instance of
T.