Extend the call site default argument expansion mechanism?

[Atila Neves]

On Friday, 11 May 2018 at 13:22:12 UTC, Meta wrote:
> On Friday, 11 May 2018 at 11:42:07 UTC, Dukc wrote:
>> On Thursday, 10 May 2018 at 14:15:18 UTC, Yuxuan Shui wrote:
>>> ...
>>> // constructor of DataStructure
>>> this(Allocator alloc=__ALLOC__) {...}
>>> ...
>>> auto alloc = new SomeAllocator();
>>> define __ALLOC__ = alloc;
>>> // And we don't need to pass alloc everytime
>>> ...
>>>
>>> Is this a good idea?
>>
>> Doesn't this basically mean including the implicits Martin 
>> Odersky talked about at Dconf in D?
>
> Yes it does. I was thinking the exact same thing while watching 
> his talk; implicits would be perfect for allocators.

D doesn't have Scala's implicits though. However, one can write 
up a reader monad in the D we have right now.

Atila