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AurevoirXavier/[Rust] Lifetime of Reference in HashMap.rs

Last active April 8, 2020 06:13
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[Rust] Lifetime of Reference in HashMap
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[Rust] Lifetime of Reference in HashMap.rs
struct Cheese<K1, K2, V> {
things: HashMap<K1, V>,
refs: HashMap<K2, &V>
}
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AurevoirXavier commented Oct 24, 2019 •
edited

KrishnaSannasi:

You can't, Rust dislikes self referential types like this, and there is no syntax to safely create them. (Actually, you can make a self referential type with safe Rust, it's just almost useless)

Even if you try and use unsafe, you can't soundly do this because HashMap reallocates on resizes, and this would invalidate all pointers into it.

More detail: https://users.rust-lang.org/t/lifetimes-of-references-in-hashmaps/33942

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