opApply Vs. Ranges: What should take precedence?

[Justin Johansson]

Bill Baxter wrote:
> On Fri, Nov 20, 2009 at 3:36 PM, Walter Bright
> <newshound1 at digitalmars.com> wrote:
>> And here I was thinking perhaps opApply should just be dumped in favor of
>> ranges.
>>
> 
> I think the opApply should take precedence.
> The only reason to define opApply is because foreach uses it.
> Ranges on the other hand are useful in other situations.
> 
> --bb

Is is absolutely necessary for opApply to take a ref parameter?  (I'm 
asking from D1 familiarity not D2 so question might not be relevant).

My understanding is that by taking a ref parameter there is an 
additional pointer dereference to get to the actual datum that is the 
subject of current application.  Of course the current regime does 
appear to allow a foreach to modify the items in the "container" being 
iterated over, though myself, I've only ever used foreach in readonly mode.

Justin Johansson