Good examples of version() algebra in real code

[Max Samukha]

On Monday, 22 May 2023 at 08:21:50 UTC, Walter Bright wrote:

>
> Personally, I like to make the core code version-independent 
> and OS-independent and hide the variances in separate modules. 
> Isn't foo() clean looking?

I sense echoes of the infamous "Clean Code" debate. Why can't we 
just let the programmer decide whether to put the versions inline 
or to hide them behind an abstraction?