Kinds of type synonym arguments

Richard Eisenberg eir at
Wed Dec 16 22:22:51 UTC 2015

On Dec 16, 2015, at 2:06 PM, Ömer Sinan Ağacan <omeragacan at> wrote:
> In any case, this is not that big deal. When I read the code I thought this
> should be a trivial change but apparently it's not.

No, it's not. Your example (`f :: (Int#, b) -> b`) still has an unboxed thing in a boxed tuple. Boxed tuples simply can't (currently) hold unboxed things. And changing that is far from trivial. It's not the polymorphism that's the problem -- it's the unboxed thing in a boxed tuple.


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