Function write_leda 

pub fn write_leda<W: Write>(
    graph: &Graph,
    vertex_labels: Option<&[String]>,
    edge_weights: Option<&[f64]>,
    writer: &mut W,
) -> IgraphResult<()>

Write a graph in LEDA native graph format.

Vertex labels are written as string attributes if provided. Edge weights are written as double attributes if provided. The reversal field for edges is always 0 (no reverse edge pointer).

Examples

use rust_igraph::{Graph, write_leda};

let mut g = Graph::with_vertices(3);
g.add_edge(0, 1).unwrap();
g.add_edge(1, 2).unwrap();

let labels = vec!["A".to_string(), "B".to_string(), "C".to_string()];
let mut buf = Vec::new();
write_leda(&g, Some(&labels), None, &mut buf).unwrap();
let s = String::from_utf8(buf).unwrap();
assert!(s.contains("LEDA.GRAPH"));
assert!(s.contains("|{A}|"));