Hi, I've come accross a small problem. I need a boxed struct that contains an array and a tree that contains references into this array. My intuition is that there shouldn't be any problem with lifetimes here, but I can't get it to work. I have simplified it to this: Rust Playground Why is a lifeti…

[image] cube: a boxed struct that contains an array and a tree that contains references into this array (It's a flyweight pattern. The array contains the shared heavy parts (less than 100) and the tree has only references to save space (thousands))

Unfortunately you can't do this as is; see the following questions: http://stackoverflow.com/q/30823880/899752 http://stackoverflow.com/q/25269597/899752 There's a problem with destruction order where the array could be destroyed before the references to elements of the array, in case your struct…

[image] mdup: Alternatively, you could replace references by indices to refer to elements in the array. Not very idiomatic Rust, but could be made to work easily. Drawbacks are: can panic if invalid index; runtime overhead of bounds checking (if you disable bound checking, this drawback morphs i…

Thank you, I will probably go with Rc for now. Might be interesting to measure performance difference between this, regular aray indices (it should make my flyweights smaller, but complicate alignment and add one indirection) and unchecked array indices ... oh well, another item on the todo list …

Struct containing reference to own field

help

cube June 23, 2015, 7:22am 2

(It's a flyweight pattern. The array contains the shared heavy parts (less than 100) and the tree has only references to save space (thousands))

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Struct containing reference to own field

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