On Thursday, 18 March 2021 at 15:04:13 UTC, rm wrote: > This makes it really complicated to use in @nogc, since you > cannot even create delegates to change things in your scope. Yes you can. There's even a unit test for this specific use-case: https://github.com/dlang/phobos/blob/8281af7310aa876f2bdeb30fd176d952141b4c96/std/sumtype.d#L2403-L2410