reference variables don't exist, but can simulate them

[Stanislav Blinov]

On Monday, 29 June 2020 at 02:11:15 UTC, NonNull wrote:

> Deprecation: Cannot use alias this to partially initialize 
> variable j of type refer. Use j._()
>
> This is for the line j=3
>
> What is this about? Where does this hidden rule come from?

That one comes from [1]. But there are quite a few more "hidden" 
rules that you're violating here. Try putting @safe on your main 
and compiling with -preview=dip1000 (for dmd, refer to your 
compiler's help if you're using others). The bulk of escape 
analysis is only done for @safe, and only with that DIP enabled 
(IIRC only some trivial checks are done otherwise).

[1] https://issues.dlang.org/show_bug.cgi?id=19441