int foundp (object obj, mixed & data, void|int remove_it)
DESCRIPTION
The given <obj> is searched in the <data> which has to be computed
by a call to search(m)(). If the <obj> is contained, the function
returns non-zero, else 0.
If <remove_it> is non-zero, the <obj> is removed from <data> so
that subsequent calls won't find it again. For this, <data> must
be passed by reference.