foreach ref very broken: fails to call front(val)

[monarch_dodra]

On Tuesday, 10 July 2012 at 14:19:04 UTC, Andrei Alexandrescu 
wrote:
>
> ...
>
> Second, the return by value from Array is intentional and has 
> to do with sealing. Array is intended to never escape the 
> addresses of its elements. That way, the collection is "sealed" 
> in the sense there can never be uncontrolled pointers to its 
> elements. This allows using efficient allocation strategies for 
> the array without compromising its safety.
>
> ...
>
> Andrei

Thanks for the reply. I had actually opened a thread about making 
Array return by ref, and you answered you thought it was a good 
point, and said that there should be an enhancement request about 
it:
http://forum.dlang.org/thread/bkozswmsgeibarowfwvq@forum.dlang.org#post-jss5iu:24qct:241:40digitalmars.com
But I guess you meant for ranges in general. I wasn't there for 
the discussions about sealed classes, so I had not considered it.

...

Anyways, still curious about that "foreach with ref" loop: Any 
chance I can expect it to work with Array in a near future? Or if 
not, shouldn't I get a compile error that you can't bind a 
reference to a temporary?

And more generally, how would code like this _ever_ work?

Array!int arr
foreach(ref a; arr)
   a += 5;

Since there is no mechanism to pass the "op" to "front"?