Mutable access to two nodes in petgraph

Question

I am using the petgraph crate to implement a dataflow graph. I would like to copy data from an edge source node to its target node. For that I would need a mutable reference to the target node and an immutable reference to the source node. However Rust's borrow checker prevents that from happening since both a mutable and immutable reference is taken to the graph at the same time.

Is there a function available in petgraph that provides mutable references to multiple nodes at the same time?

How about [index_twice_mut](https://docs.rs/petgraph/0.4.3/petgraph/graph/struct.Graph.html#method.index_twice_mut) ? — Chris Emerson, Feb 23 '17 at 22:05

score 2 · Accepted Answer · answered Feb 23 '17 at 22:26

2

The [index_twice_mut] method is the way to do that.

Note that it panics if you try to index the same object twice, so you need to check that first.

answered Feb 23 '17 at 22:26

Chris Emerson

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Mutable access to two nodes in petgraph

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