#16310: Program fails with "Impossible case alternative" when optimized -------------------------------------+------------------------------------- Reporter: RyanGlScott | Owner: (none) Type: bug | Status: closed Priority: normal | Milestone: Component: Compiler | Version: 8.6.3 Resolution: wontfix | Keywords: TypeInType Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: Runtime crash | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by simonpj): `unsafeCoerce` is certainly dangerous, as its name suggests! Here `axiom` seems to claim that for all types `a` and `b`, the two are equal. That might lead to a seg-faolt; here it leads to "unreachable" code being reached. Or is there more to it than that? -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16310#comment:5 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler