Should the comma operator be removed in D2?

[downs]

Robert Jacques wrote:
> On Tue, 17 Nov 2009 00:06:27 -0500, Yigal Chripun <yigal100 at gmail.com>
> wrote:
> 
>> Robert Jacques wrote:
>>> On Mon, 16 Nov 2009 17:53:45 -0500, Stewart Gordon
>>> <smjg_1998 at yahoo.com> wrote:
>>>
>>>> dsimcha wrote:
>>>> <snip>
>>>>> Axe.  Looks like the only things it's good for are making code
>>>>> undreadable and
>>>>> abusing for loop syntax to...
>>>>>  Make code unreadable.
>>>> <snip>
>>>>
>>>> Suppose you want the increment of a for loop to change two variables
>>>> in parallel.  I don't call that making code unreadable.
>>>>
>>>> Stewart.
>>>  Yes the classic use case of the comma operator is multi-variable
>>> declarations/increments in a for loop.
>>
>> This was argued before and as I and others said before, this is *not*
>> a use case for the comma separator.
>>
>> e.g.
>> for (int a = 0, b = 1; condition(); a++, b++) {...}
>>
>> int a = 0, b = 1 // this is a declaration and not an expression
>>
>> a++, b++ // isn't assigned to any variable and can be treated as a tuple
>>
>> the only use case that will break is if the two increments are
>> dependent on the order (unless tuples are also evaluated from left to
>> right):
>> e.g.
>> a + 5, b + a //
>>
>> I doubt it very much that anyone ever uses this, it's too unreadable
>> to be useful.
> 
> However, I imagine tuple(a++,b++) would have some overhead, which is
> exactly what someone is trying to avoid by using custom for loops.
> 
> Personally, I like using a..b => tuple(a,b), since it also solves the
> multi-dimensional slicing and mixed indexing and slicing problems.

Zero overhead. Tuples are flat compile-time entities.