
5 Oct
2012
5 Oct
'12
7:06 a.m.
| Does this imply forbidding user-written instances of Typeable? If yes, | then I guess some currently accepted programs would also be rejected | (those with manual instances)? Yes, that's the idea; I should have said that. Allowing users to write instances leads to potential un-soundness when doing dynamic type casts, so it has always been a Bad Idea. Simon