hasDataMember and mixin inconsistency

[Philippe Sigaud]

>> Just testing whether t.M can be assigned to something (ie, is it a value?)
>> I use '_' as a variable name to indicate I don't care for it's precise
>> name/value. It's just a placeholder.
>
>
> Ok, I must be missing something, why "t.D" or is this just a typo?

Ark, typo, sorry about that.


> And secondly wouldn't "x.M = y.M" take care of checking that the member can be
> read and written to ?

t.M = t.M? Yes, you're right.

> Also, doesn't your solution require T to be default constructible ?

Yes, but if a type is not default-constructible, I don't know how to test it.
Maybe testing on typeof(T.M)?


>> Using 2.061 here.
>
>
> Well that was the problem! I was still using 2.060 which seems to have the
> bug. Now that I've moved to 2.061 everything works as expected (your
> implementation and mine).

Great!