diff options
Diffstat (limited to 'libraries/base/Unsafe')
| -rw-r--r-- | libraries/base/Unsafe/Coerce.hs | 12 |
1 files changed, 10 insertions, 2 deletions
diff --git a/libraries/base/Unsafe/Coerce.hs b/libraries/base/Unsafe/Coerce.hs index 00444bd107..e911c6fc57 100644 --- a/libraries/base/Unsafe/Coerce.hs +++ b/libraries/base/Unsafe/Coerce.hs @@ -14,8 +14,16 @@ -- it is your responsibility to ensure that the old and new types have -- identical internal representations, in order to prevent runtime corruption. -- --- 'unsafeCoerce' is just a trivial wrapper for 'unsafeCoerce#'; --- see the latter for important documentation about correct usage. +-- 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. module Unsafe.Coerce (unsafeCoerce) where |