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0 pointslikeliv6y ago0 comments

It is perfect fine to take by value something that is not Copy to transfer its ownership.

It is a compiler error to use the value after it was moved. And the compiler error is quite explicit about how to solve it

For example you can explicitly clone

    let y = add(x.clone());
    let z = add(x);

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dorfsmay6y ago

What would be cases where the add() function need ownership of the x?

What the chance in real life that a function like that cannot simply use a reference?

In my learning Rust, my life became significantly better and easier when I started to references to borrow as much as possible.

likelivOP6y ago

That was just an example. But maybe 'x' is a BigInt type that use a memory allocation to store its contents. The ownership would be transferred to the return value

dorfsmay6y ago

But again, what would be the drawback(s) of using a pointer instead of transfering the ownership?

Not rethorical, I'm genuinely curious as I used to struggle with the copy vs move decisions, and a bunch of issues with ownership which went all away when I started using pointer/borrowing everywhere.

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dorfsmay6y ago

What would be cases where the add() function need ownership of the x?

What the chance in real life that a function like that cannot simply use a reference?

In my learning Rust, my life became significantly better and easier when I started to references to borrow as much as possible.

likelivOP6y ago

That was just an example. But maybe 'x' is a BigInt type that use a memory allocation to store its contents. The ownership would be transferred to the return value

dorfsmay6y ago

But again, what would be the drawback(s) of using a pointer instead of transfering the ownership?

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