SumType in Phobos?

[Panke]

On Wednesday, 19 February 2020 at 17:37:25 UTC, H. S. Teoh wrote:
> when you cannot be certain that the user is using a compatible 
> version of Phobos with a compatible version of the compiler.  
> Remember how in the old days people used to have stray copies 
> of phobos/druntime lying around their filesystem, and it would 
> lead to obscure ICEs and other inscrutable problems that 
> "magically" go away when they purge all copies of 
> phobos/druntime and reinstall?  That's the kind of breakage 
> we'd have to deal with if we went this route, except this time 
> it will be worse because now users will say, "but I'm using the 
> official dub version of Phobos, why is that not supported?".
>
>
> T

This could be solved by increasing the major version and 
requiring a minimum version of the compiler frontend as some 
libraries already do.