second draft: add Bitfields to D

[Timon Gehr]

On 5/4/24 03:45, Walter Bright wrote:
> On 4/30/2024 3:00 AM, Timon Gehr wrote:
>> On 4/30/24 05:14, Walter Bright wrote:
>>> I do not recall exactly why this `ref` behavior was done for foreach, 
>>> but it was either a mistake or was done precisely to make generic 
>>> code work.
>>
>> You mean fail silently.
> 
> No, I did not mean that.

Well, that is what it will do if you assign a value to the `ref` 
iteration variable.