struct opCmp?

[BCS]

Hello Nick,

> Yea, I agree. But at the very least, I was thinking that we could use
> a warning when opCmp is defined and opEquals isn't. Can anyone think
> of a reasonable case where it would actually make sense to override
> opCmp, but not opEquals? (that is, without bastardizing them like in a
> "C++ streams" kind of way)
> 

what about where you want to disallow == like with floating point like cases? 
I know it doesn't work this way, but if you define opCmp and not opEquals, 
I wouldn't mind ==/!= being defined to unimplemented.