Map<SparseMatrix> is not documented

Submitted by Christoph Hertzberg @chhtz

Assigned to Nobody

Link to original bugzilla bug (#1180)
Version: 3.3 (current stable)

Description

I could not find any documentation for sparse maps in our documentation.
I think this is essential for the 3.3 documentation (unless that feature is not considered stable yet?)

Blocking

#558 (closed)