Sure, but writing a graph (any kind, but even more so undirected) in a language without GC is a minefield from the standpoint of memory safery. You simply need

Sure, but writing a graph (any kind, but even more so undirected) in a language without GC is a minefield from the standpoint of memory safery. You simply need some kind of reference counting. High-level languages like C# and F# hide this need behind using GC for everything, but Rust tries to be lower level than those and therefore exposes the extra layer.