#10532: Unnecessary constraints when using overlapping instances -------------------------------------+------------------------------------- Reporter: MikeIzbicki | Owner: Type: bug | Status: new Priority: normal | Milestone: Component: Compiler (Type | Version: 7.10.1 checker) | Keywords: Resolution: | Architecture: Operating System: Unknown/Multiple | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Revisions: -------------------------------------+------------------------------------- Comment (by goldfire): Because, without overlapping instances, GHC can make a unique correct choice about what instance of `Foo` to use. With the overlapping instances, there is ambiguity which must be resolved. -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/10532#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler