allMembers broke for __

[Walter Bright]

On 6/15/2018 11:08 PM, DigitalDesigns wrote:
> When an identifier starts with __, allMembers does not return it. This is very 
> bad behavior! It can silently create huge problems if the programmer is not 
> aware of the bug.


It's not a bug, it's quite deliberate:

   https://github.com/dlang/dmd/blob/master/src/dmd/traits.d#L1385


Identifiers starting with __ are reserved for the implementation:

   https://dlang.org/spec/lex.html#identifiers

They have implementation-defined behavior. Do not use them in user code.