#9429: Alternative to type family Any -------------------------------------+------------------------------------- Reporter: mboes | Owner: Type: feature | Status: new request | Milestone: Priority: normal | Version: 7.9 Component: Compiler | Keywords: Resolution: | Architecture: Unknown/Multiple Operating System: | Difficulty: Unknown Unknown/Multiple | Blocked By: Type of failure: | Related Tickets: 9097, 9380 None/Unknown | Test Case: | Blocking: | Differential Revisions: | -------------------------------------+------------------------------------- Comment (by tibbe): There's another use of `Any` that I'm aware of that might not work anymore, to create unique tombstone values that can be compare using `reallyUnsafePtrEquality#`. See e.g. https://github.com/gregorycollins/hashtables/blob/8a1ed23450377360e4b53b83c5.... These tricks allow you to write a `Maybe a` represents null values (or any number of unary constructors) using a designated pointer instead of an indirection. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9429#comment:15 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler