template <class NODECNT> ostream& writeNodes(ostream &o,const NODECNT &cnt)

This template function writes a container of nodes to a stream.

NODECNT should be a container as defined by the STL
*NODECNT.valuetype must have a method writeTo(ostream&)

The data written to the stream will be of this form:

<size of the container>
(<address of node> [<additional info>] )*