#8827: Inferring Safe mode with GeneralizedNewtypeDeriving is wrong -------------------------------------+------------------------------------- Reporter: goldfire | Owner: Type: bug | Status: new Priority: normal | Milestone: 7.12.1 Component: Compiler | Version: 7.9 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: None/Unknown | Unknown/Multiple Blocked By: | Test Case: Related Tickets: 8226, 8745 | Blocking: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by simonpj): The GHC 7.6 user manual [https://downloads.haskell.org/~ghc/7.6.3/docs/html/users_guide/safe- haskell.html#safe-language used to say]: ''GeneralizedNewtypeDeriving — It can be used to violate constructor access control, by allowing untrusted code to manipulate protected data types in ways the data type author did not intend, breaking invariants they have established.''. But that was removed in [https://downloads.haskell.org/~ghc/7.8.2/docs/html/users_guide/safe- haskell.html#safe-language the 7.8 user manual], which seems to contradict the conclusion in comment:36. Would someone like to fix the manual to say what it should say, whatever that now is? See [https://mail.haskell.org/pipermail/haskell- cafe/2015-April/118970.html this Haskell Cafe thread]. Simon -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/8827#comment:38 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler