Regarding Issue 9423

[Maxim Fomin]

On Wednesday, 30 January 2013 at 11:10:17 UTC, bearophile wrote:
> Currently you are allowed to write a lambda literal as in line 
> 3, but you can't omit "ref" as in line 4:
>
>
> void foo(int delegate(ref int[1]) spam) {}
> void main() {
>     foo((ref x) => 0); // line3, OK
>     foo(x => 0); // line4, Error
> }
>
>
> Do you think "ref" annotation should be required at the call 
> site?
>
> This is the Bugzilla thread. Hara has already implemented the 
> "ref" inference, but he's not sure if it's a good idea:
>
> http://d.puremagic.com/issues/show_bug.cgi?id=9423
>
> Bye,
> bearophile

By the way, recently problem with functions taking by ref and 
returning passed ref was discussed and was considered to be a 
@safity hole. If your proposal is accepted, issue with ref and 
@safe may be needed to be taken into account in application to 
your proposal.