The future of lambda delegates

[Bruno Medeiros]

Oskar Linde wrote:
> 
> What could improve things is if there was a no-immigrants (only visitors)
> declaration for function arguments that guaranteed that any escaping
> delegate passed to one such function argument would never be stored after
> that function returns or be passed as argument to any other immigration
> friendly function:
> 
> void update(int[] arr, visitor void delegate(inout int a) updater) {
>         foreach(inout i;arr)
>                 updater(i);
> }
> 
> ....
> int b = ...; 
> myarr.update((inout int a) { a += b; }); 
> // would not count as an escape and would not need b to be stack allocated
> 
> /Oskar
> 

Whoa... if I'm not mistaken that is kinda like the converse of 
const(read-only): it is a write-only (or use-only) variable. It's value 
cannot be read (at least directly) :

   mydg = updater;  // cannot be read!
   updater(i);      // but can use;
   updater = xpto;  // and can assign to?

:D

-- 
Bruno Medeiros - MSc in CS/E student
http://www.prowiki.org/wiki4d/wiki.cgi?BrunoMedeiros#D