这很简单,您需要通过引用绑定:
/// Add a directional edge that starts at `from_node` and points to `to_node`.
pub fn add_edge(&mut self, from_node : usize, to_node : usize) {
match self.outgoing_edges[from_node] {
Some(ref mut set) => { set.insert(to_node); },
None => { self.outgoing_edges[from_node] = Some(hashset!{ to_node }); }
}
match self.incoming_edges[to_node] {
Some(ref mut set) => { set.insert(from_node); },
None => { self.incoming_edges[to_node] = Some(hashset!{ from_node }); }
}
}
或者与人体工程学特征相匹配
binding mode
/// Add a directional edge that starts at `from_node` and points to `to_node`.
pub fn add_edge(&mut self, from_node : usize, to_node : usize) {
match &mut self.outgoing_edges[from_node] {
Some(set) => { set.insert(to_node); },
None => { self.outgoing_edges[from_node] = Some(hashset!{ to_node }); }
}
match &mut self.incoming_edges[to_node] {
Some(set) => { set.insert(from_node); },
None => { self.incoming_edges[to_node] = Some(hashset!{ from_node }); }
}
}