On Tuesday, 4 February 2020 at 07:44:08 UTC, mark wrote: > Just found this post by Mark Parker that explains: > https://forum.dlang.org/post/gvveit$10i5$1@digitalmars.com I recommend using Nullable from https://dlang.org/phobos/std_typecons.html#Nullable if you want to explicitly allow a non-value. I think it's cleaner and shows the intent better.