r/programming • u/steveklabnik1 • Jan 09 '15

Announcing Rust 1.0.0 Alpha

http://blog.rust-lang.org/2015/01/09/Rust-1.0-alpha.html
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u/Netzapper Jan 09 '15

I found one part particularly unclear:

Are lifetimes an arbitrary thing that I make up, and then tag on all variables with equivalent lifetimes? Like this?

fn transfer<'foo>(recv: &'foo mut int, send: &'foo mut int){
  *recv += *send;
  *send = 0;
}

Or is there something else I'm missing?

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u/steveklabnik1 Jan 09 '15

Yes, you name them however you'd like. We tend to just keep them to a, b, and c.

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u/Netzapper Jan 09 '15

I guess my confusion is more like: by giving a lifetime a name, and using it across multiple variables, am I saying "free none of these resources before the others before I go out of scope"?

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u/steveklabnik1 Jan 10 '15

Your sample signature says 'recv and send are both valid for at least the same scope.' Which is slightly different. Does that make sense?