Add missing Monad/Traversable instances to tuples

[Niklas Hambüchen]

As somebody who's seen stuff like

  > sum (1,2)
  2

sneak into production code, I am also very scared of having more of it.

I would be super appreciative of any technical solution that allows those that want these instances to opt into having them, while making it possible to not have them in most business logic code.

On 02/04/2019 9:40 AM, Matthew Pickering wrote:
> To repeat the main reason: this change introduces bugs into programs
> which are very hard to detect.