newtype abstraction problem

Alastair Reid alastair at
Wed Feb 4 10:04:42 EST 2004

> I can't see a simple solution.  Perhaps we just declare that when a
> newtype is exported abstractly, it's suitability as a foreign argument
> type is still visible.

This feels a little like the global visibility of class instances.
If I export a type T abstractly, all its instances are exported too.
(In that sense, SimonPJ's old CCallable/CReturnable classes were right on the 


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