On Wed, Jul 10, 2013 at 5:59 PM, Patrick Walton <[email protected]> wrote: > Hi everyone, > > Currently there's a problem with repeated vector expressions (`[0, ..n]`): > the value must be copyable. I would like to change this to implicit > copyability changing as part of the migration to `Clone`, which makes this > even more restrictive. > > This makes it impossible (without writing a very long literal) to have > something reasonable like `[None, ..4096]` with the value as `Option<~T>`, > since `Option<~T>` is not implicitly copyable. > > The easiest way that I can see to fix this is to treat `EXPR` in `[EXPR, > ..COUNT]` as evaluated once for each `COUNT`. Essentially it becomes a > thunk. This makes me slightly nervous, but I don't see anything wrong with > it semantically. > > Thoughts? > > Patrick
How about we start by allowing the subset of expressions that are constant expressions? I think it would be a reasonable limitation. _______________________________________________ Rust-dev mailing list [email protected] https://mail.mozilla.org/listinfo/rust-dev
