GHC 8 allows ambiguous type without AllowAmbiguousTypes
This module compiles with GHC 8:
{-# LANGUAGE DefaultSignatures #-}
-- {-# LANGUAGE AllowAmbiguousTypes #-} -- Not required with GHC 8.0.1.
module T12151 where
class Put a where
put :: a
default put :: t -- This should be `a` instead of `t`
put = undefined
GHC 7.10 required AllowAmbiguousTypes
, to defer the ambiguity check to use sites.
(Example extracted from the description of #7437 (closed))
Trac metadata
Trac field | Value |
---|---|
Version | 8.0.1 |
Type | Bug |
TypeOfFailure | OtherFailure |
Priority | normal |
Resolution | Unresolved |
Component | Compiler (Type checker) |
Test case | |
Differential revisions | |
BlockedBy | |
Related | |
Blocking | |
CC | |
Operating system | |
Architecture |