Overload comparison operators for "nullable" types

[Oleg B]

On Thursday, 30 July 2020 at 14:52:17 UTC, H. S. Teoh wrote:
> On Thu, Jul 30, 2020 at 01:41:05PM +0000, Oleg B via 
> Digitalmars-d-learn wrote: [...]
>> Logically we can compare versions, but what must return 
>> `opCmp` if one of versions has 'not comparible' state?
> [...]
>
> opCmp is allowed to return float; so you could return float.nan 
> in this case.
>
>
> T

Thank you! Simple answer but not in documentation...