#8827: Inferring Safe mode with GeneralizedNewtypeDeriving is wrong -------------------------------------+------------------------------------ Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.8.1 Component: Compiler | Version: 7.8.1-rc2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Unknown/Multiple Type of failure: None/Unknown | Difficulty: Unknown Test Case: | Blocked By: Blocking: | Related Tickets: 8226, 8745 -------------------------------------+------------------------------------ Comment (by ekmett): One option here is to just retain the status quo that `GeneralizedNewtypeDeriving` isn't available in `Safe` Haskell. Then you'd retain the invariant that GND absolutely can't be used to violate library invariants, and since `coerce` isn't available in `Safe` mode without explicit trust, the interaction of these two features goes away completely. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8827#comment:22 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler