Lambda capture by value

[JN]

On Monday, 24 February 2020 at 20:00:20 UTC, Adam D. Ruppe wrote:
> On Monday, 24 February 2020 at 19:50:23 UTC, JN wrote:
>>     foreach (i; iota(5))
>>     {
>>         printers[i] = () { write(i); };
>
> I know it looks silly but if you make that:
>
>          printers[i] = (int i) { return () { write(i); }; }(i);
>
> it will do what you want.
>
> This is something that used to be common in javascript, write a 
> little function that passes the capture-by-value args and 
> returns the lambda you actually want and call it immediately.
>
> That extra layer causes the compiler to create a new copy of 
> the capture variables snapshotted in time.

D'oh! I am actually familiar with the pattern from Javascript, 
used it many times, but somehow got it mixed up with something 
else and couldn't make it work.

Thanks.