I have asked this on StackOverflow[1]. I have received a valid
answer, which solves my problem, however, I have still not
understood, why some versions of it work and some don't.
The code is here[2].
I don't understand why `a` compiles just fine, while `b` and `c`
don't.
I think, that I don't understand what `void function()` does or
is.
Can someone explain it to me?
And I don't see why `(){}` works and `() => {}` does not.
[1]:
https://stackoverflow.com/questions/64581514/void-lambda-function/64587101#64587101
[2]: https://run.dlang.io/is/GFe9Ht
