Strange closure behaviour

[Emmanuelle]

On Saturday, 15 June 2019 at 00:30:43 UTC, Adam D. Ruppe wrote:
> On Saturday, 15 June 2019 at 00:24:52 UTC, Emmanuelle wrote:
>> Is it a compiler bug?
>
> Yup, a very longstanding bug.
>
> You can work around it by wrapping it all in another layer of 
> function which you immediately call (which is fairly common in 
> javascript):
>
>         funcs ~= ((x) => (int i) { nums[x] ~= i; })(x);
>
> Or maybe less confusingly written long form:
>
>         funcs ~= (delegate(x) {
>             return (int i) { nums[x] ~= i; };
>         })(x);
>
> You write a function that returns your actual function, and 
> immediately calls it with the loop variable, which will 
> explicitly make a copy of it.

Oh, I see. Unfortunate that it's a longstanding compiler bug, but 
at least the rather awkward workaround will do. Thank you!