No need opUnary

[Salih Dincer]

On Sunday, 18 December 2022 at 21:17:02 UTC, j wrote:
> Why are you using `@property` everywhere?

You are right but if I don't use it for `opCall()` the output 
will be like `S(9)`.  Likewise, if I don't use `inout`, the 
program is terminated.

I think it's a bug with `std.format` that I said last time. 
Because in old versions it works whether you use `inout` or not.

SDB at 79