opCmp, [partial/total/pre]orders, custom floating point types etc.

[John Colvin via Digitalmars-d]

On Wednesday, 13 January 2016 at 01:39:26 UTC, John Colvin wrote:
> On Wednesday, 13 January 2016 at 00:31:48 UTC, Andrei 
> Alexandrescu wrote:
>> [...]
>
> I would completely agree, except that we have builtin types 
> that don't obey this rule. I'd be all in favour of sticking 
> with total orders, but it does make it hard (impossible?) to 
> make a proper drop-in replacement for the builtin floating 
> point numbers (including wrappers, e.g. std.typecons.Typedef 
> can't handle nans correctly) or to properly handle comparisons 
> between custom types and builtin floating points (as mentioned 
> by tsbockman).
>
> I am all for keeping it simple here, but I still think there's 
> a problem.

https://issues.dlang.org/show_bug.cgi?id=15561