base- Basic libraries

CopyrightMalcolm Wallace 2006
LicenseMalcolm Wallace 2006
Safe HaskellUnsafe



The highly unsafe primitive unsafeCoerce converts a value from any type to any other type. Needless to say, if you use this function, it is your responsibility to ensure that the old and new types have identical internal representations, in order to prevent runtime corruption.

The types for which unsafeCoerce is representation-safe may differ from compiler to compiler (and version to version).

  • Documentation for correct usage in GHC will be found under unsafeCoerce# in GHC.Base (around which unsafeCoerce is just a trivial wrapper).
  • In nhc98, the only representation-safe coercions are between Enum types with the same range (e.g. Int, Int32, Char, Word32), or between a newtype and the type that it wraps.