Module type Imperative.Matrix.S

module type S = sig .. end

Vertices are integers in 0..n-1. A vertex label is the vertex itself. Edges are unlabeled.
include Sig.I
val make : int -> t
Creation. graphs are not resizeable: size is given at creation time. Thus make must be used instead of create.

Note: add_vertex and remove_vertex have no effect. clear only removes edges, not vertices.