Proposal: add ordNub somewhere in containers

[Henning Thielemann]

On Mon, 16 Oct 2017, David Feuer wrote:

> I would imagine
> 
> ordNub :: (Foldable t, Ord a)
>        => t a -> [a]


The kind of generalization where the input is Foldable but the output is 
just a list looks pretty unnatural to me. I think it means that we still 
do not have the proper generalization that allows us to define

   ordNub :: (??? f, Ord a) => f a -> f a

I would just leave it as ordNub :: (Ord a) => [a] -> [a]