Function petgraph::algo::is_cyclic_directed

pub fn is_cyclic_directed<G>(g: G, space: Option<&mut DfsSpace<G::NodeId, G::Map>>) -> bool where G: IntoNodeIdentifiers + IntoNeighborsDirected + IntoExternals + Visitable

[Generic] Return true if the input directed graph contains a cycle.

If space is not None, it is reused instead of creating a temporary workspace for graph traversal.