A shared reference, &T is , as the name implies, a pointer that may be shared. Any number of references may exist to the same value, and each shared reference is Copy, so you can trivially make more of them

I don't understand why a shared reference has to implement copy. In fact, isn't this not true just by the fact that references work for Strings and Strings size can't be known at compile time?

I'm having trouble with the idea of assigning a new value to a mutable reference.

let mut x = Box::new(42); *x = 84;

Why in this example, is the assignment dereferenced. Why not just do x=84? is it dereferenced specifically because is Boxed on the heap?

you are viewing a single comment's thread
view the rest of the comments

[–] nerdblood 1 points 1 year ago

I think where I was getting hung up here as I was still thinking of the value of the reference rather than the reference itself. That's why I brought up Strings, it didn't make sense that String would automatically implement Copy since they go on the heap. But I see now we're talking about the pointer reference TO that value.

Thanks!