blob: 9b1e3605beb0ce152a627b9d9abeba464d85cfda (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
|
{-# OPTIONS_GHC -XNoImplicitPrelude #-}
-----------------------------------------------------------------------------
-- |
-- Module : Unsafe.Coerce
-- Copyright : Malcolm Wallace 2006
-- License : BSD-style (see the LICENSE file in the distribution)
--
-- Maintainer : libraries@haskell.org
-- Stability : experimental
-- Portability : portable
--
-- 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.
module Unsafe.Coerce (unsafeCoerce) where
#if defined(__GLASGOW_HASKELL__)
import GHC.Base (unsafeCoerce#)
unsafeCoerce :: a -> b
unsafeCoerce = unsafeCoerce#
#endif
#if defined(__NHC__)
import NonStdUnsafeCoerce (unsafeCoerce)
#endif
#if defined(__HUGS__)
import Hugs.IOExts (unsafeCoerce)
#endif
|
