\begin{ccRefConcept}{Sublayer}

\ccDefinition

Defines the requirements that a
\ccStyle{Sublayer_type} of class \ccStyle{Range_tree_d}
or \ccStyle{Segment_tree_d} has to fulfill.

First of all, the class has to be derived from the abstract base
class \ccStyle{Tree_base} and therefore
has to provide  methods
\ccStyle{make\_tree}, \ccStyle{window\_query},
\ccStyle{enclosing\_query} and
\ccStyle{is\_inside}
with the same parameter types as the instantiated class
\ccStyle{Range\_tree\_d} or \ccStyle{Segment\_tree\_d},
respectively.
Furthermore a method \ccStyle{bool
  is\_anchor()} has to be provided. If the \ccStyle{Sublayer\_type} class
 builds a recursion anchor for class
\ccStyle{Segment\_tree\_d}, this function is expected to
return \ccStyle{true}, \ccStyle{false} otherwise.

Such a recursion anchor class is provided by the class  class.
\ccc{Tree_anchor<Data, Window>}.
\end{ccRefConcept}