Is there a way to see if .init has been set by the user?

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On Saturday, 21 September 2013 at 14:11:44 UTC, simendsjo wrote:
> On Saturday, 21 September 2013 at 13:55:00 UTC, Dicebot wrote:
>> On Saturday, 21 September 2013 at 13:48:00 UTC, simendsjo 
>> wrote:
>>> On Saturday, 21 September 2013 at 13:38:44 UTC, Dicebot wrote:
>>>> On Saturday, 21 September 2013 at 13:30:19 UTC, simendsjo 
>>>> wrote:
>>>>> I'm though of using if for aggregates, yes. But this 
>>>>> doesn't handle the case where you set the same value is 
>>>>> T.init.
>>>>
>>>> I don't think those two case are any different from the type 
>>>> system point of view, manual or default.
>>>
>>> Need some __traits(hasUserSuppliedInit, T) then :)
>>
>> I am not sure those differ even at compiler level (other than 
>> at syntax stage) - why would you need it?
>
> I was thinking of "query by example". If a field has been set, 
> it should be used in a where clause. But if I cannot see the 
> difference between int.init and 0 for instance, it is 
> impossible to get it right.
> It's possible to solve this using UDAs of course.

0 and int.init is the same. ;)