| Copyright | (c) The University of Glasgow 2009 | 
|---|---|
| License | see libraries/ghc-prim/LICENSE | 
| Maintainer | cvs-ghc@haskell.org | 
| Stability | internal | 
| Portability | non-portable (GHC Extensions) | 
| Safe Haskell | Unsafe | 
| Language | Haskell2010 | 
GHC.Magic.Dict
Description
Defines the withDict function. For more information, see
 Note [withDict] in GHC.Tc.Instance.Class in GHC.
 The definition of withDict is located in a separate module from
 GHC.Magic because withDict is Unsafe (it threatens type class
 coherence) while GHC.Magic is Trustworthy.
Use GHC.Exts from the base package instead of importing this
 module directly.
Synopsis
- class WithDict cls meth where- withDict :: forall {rr :: RuntimeRep} (r :: TYPE rr). meth -> (cls => r) -> r
 
Documentation
class WithDict cls meth where Source #
The constraint WithDict cls methcls can be provided in the form of a dictionary of
 type meth. This requires cls to be a class constraint whose single
 method has type meth.
For more (important) details on how this works, see
 Note [withDict] in GHC.Tc.Instance.Class in GHC.
Since: ghc-prim-0.9.0
Methods
withDict :: forall {rr :: RuntimeRep} (r :: TYPE rr). meth -> (cls => r) -> r Source #