pub trait AddVertex<V, E>where
E: Ord,{
// Required method
fn add_vertex(&mut self, x: V) -> Option<BTreeSet<E>>;
}
Expand description
AddVertex
adds the vertex x, if it is not there.
§Example
use btree_graph::{BTreeGraph, AddVertex, Vertices};
use std::collections::BTreeSet;
let mut graph: BTreeGraph<String, usize> = BTreeGraph::new();
let old_vertex_value: Option<BTreeSet<usize>> = graph.add_vertex(String::from("origin"));
assert!(old_vertex_value.is_none());
assert_eq!(graph.vertices().len(), 1)