Monad instance for Monoid e => (,) e

[Henning Thielemann]

On Thu, 25 Jul 2013, Nathan van Doorn wrote:

> This is a relatively simple instance, so I was surprised that I couldn't find it in base.
> My proposal is to add the instance to Control.Monad.Instances, undeprecating the module.

Wasn't it already added? Nonetheless, I strongly suggest to use 
Control.Monad.Trans.Writer instead. To me, using a pair as a monad looks 
like an error not like a feature.