Sum Type by Struct

[Paul Backus]

On Friday, 13 September 2024 at 11:16:15 UTC, Nick Treleaven 
wrote:
> That's great. Otherwise you would have to define empty struct 
> types and they would probably waste one byte of space:

Perhaps the real issue here is the D language's inability to 
express a zero-sized user-defined unit type, and this issue 
deserves a solution that isn't tightly coupled to some other new 
language feature.