https://issues.dlang.org/show_bug.cgi?id=23998
--- Comment #3 from Dennis <[email protected]> --- @mustuse is supposed to prevent discarding values of that type. I'm not a fan of tacking on additional rules about `opCast` to a feature that should be simple and orthogonal. It looks like what you really want is type state, which Timon Gehr has been advocating for, but that would require a DIP. --
