#9163: Ptr should have a phantom role -------------------------------------+------------------------------------- Reporter: simonpj | Owner: (none) Type: bug | Status: closed Priority: normal | Milestone: 7.10.1 Component: Compiler | Version: 7.8.2 Resolution: fixed | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: | roles/should_compile/Roles2 Blocked By: | Blocking: Related Tickets: #9164 | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by dominic): I do feel strongly. From https://hackage.haskell.org/package/base-4.8.2.0/docs/Data-Coerce.html: "The function coerce allows you to safely convert between values of types". If the user has to know that the package they are using uses Ptr and thus avoid coerce then that seems to break the principle of abstraction. At least change the claim that coerce is type safe. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/9163#comment:37 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler