| Safe Haskell | None |
|---|---|
| Language | Haskell2010 |
Witch.Cast
Documentation
class Cast source target where Source #
This type class is for converting values from some source type into
some other target type. The constraint Cast source target measn that
you can convert from a value of type source into a value of type
target.
This type class is for conversions that cannot fail. If your conversion can
fail, consider implementing TryCast instead.
Minimal complete definition
Nothing
Methods
cast :: source -> target Source #
This method implements the conversion of a value between types. At call
sites you will usually want to use from or into instead of this
method.
The default implementation of this method simply calls coerce,
which works for types that have the same runtime representation. This
means that for newtypes you do not need to implement this method at
all. For example:
>>>newtype Name = Name String>>>instance Cast Name String>>>instance Cast String Name