copy-ctor's

[Ola Fosheim Grøstad]

On Monday, 27 May 2019 at 00:41:22 UTC, Manu wrote:
> Well I'm obviously implementing a tagged union.
> The language just needs to make the feature available, and let 
> me wrap it up.

IIRC Bearophile suggested that the struct could provide a 
function or some mechanism that would tell the runtime what type 
the union contained. But Andrei didn't like it.

Some sort of "type-switch" statement in the union with a 
conditional that is allowed to reference fields in the 
surrounding struct would be a possibility.

The real problem isn't that one cannot come up with a decent 
solution, but that the semantics of C has been subsumed, and 
extended.