On Sep 25, 2013, at 2:58 PM, Jack Moffitt <j...@metajack.im> wrote:
>>>> Miss it? Did it ever work? This seems like a bug though. Mutability is
>>>> inherited, so without this there's no way to do mutable destructuring
>>>> bind right?
>>> Apparently it went away in commit f9b54541 and the workaround used there
>>> is `let (foo, bar) = ...; let mut foo = foo;` etc.
>>>
>>> Seems intentional, but I don't recall the rationale.
>>
>> The eventual plan is to say `let (mut foo, bar) = ...;`. We just don't yet
>> support that.
>
> The commit's intention as i recall was to change this `let mut foo,
> bar;` which would make bar mutable. I'm not sure the intent was to
> affect destructuring bind.
>
> While `let (mut foo, bar)` matches pattern syntax for tuples, it seems
> weird for structs, although I guess it probably matches there too.
>
> `let mut Foo { x: x, y: y } = some_foo;` seems better than `let Foo {
> mut x: x, mut y: y} = some_foo;`. Seems like both are probably
> reasonable to have.
>
> I don't feel super strongly about this, I just thought it weird that
> destructuring let doesn't work with mut in the obvious (to me anyway)
> way.
I believe the intention was to allow `mut` in the same places you could put
`ref` today in a pattern match.
-Kevin
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