Difference between foo(x:real(?w)) and foo(x:?R) where isReal(R)

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Sorry. I know I have asked this before but I cannot find the answer.

Thanks - Damian

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Hi Damian —

I think of these as being near-equivalent, in the sense that they are both generic, albeit using slightly different approaches ("any real" vs. "any type as long as that type is a real"). They also have (likely obvious) different naming impacts (the former will give you a param w that's the real's bitwidth; the latter gives you a type alias R representing the specific real type).

Of the two, I find the former to be the preferable form because it states the intention in a clearer and more up-front way, whereas using the where clause for a case like this feels like more of an afterthought / late specification of a constraint (where again, I read it as "This can be any type, but only if that type is a real" which feels a bit roundabout to me).

-Brad

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