Inconsistency between `AllMembers` and `hasMember`

[Stanislav Blinov]

On Sunday, 18 November 2018 at 00:51:51 UTC, drug wrote:
> On 18.11.2018 1:26, Adam D. Ruppe wrote:
>> 
>> That's because the compiler passes it a hidden pointer to 
>> refer to the context outside. The compiler could perhaps be 
>> smarter about it, and see if those methods actually refer to 
>> the context, but it seems to simply say if the method is 
>> there, it might refer to it and it adds the context pointer 
>> (note that S.sizeof increases too) and a magic constructor to 
>> set it.
> Well, if "this" means hidden pointer then it never should be 
> returned by AllMembers at all, isn't it?

It's only "hidden" in that there's no symbol to access it. But 
you can still access it via .tupleof, and it still of course 
affects the ABI (i.e. S.sizeof is always at least pointer size 
when S is nested).
If you want to iterate fields, .tupleof is a better way to do it. 
As for that hidden pointer, you can just test with 
__traits(isNested, S) whether that's present, and just don't look 
at the last field.