provides the Generic mapping between the wrapper type and the wrapped
value type. Using a Repr type of V :: HNil proves that W wraps
a single value of type V
a Validator instance that will validate a value of type V in the context
of a wrapper of type W. The Validator object provides a low-priority instance
which is an identity function (i.e. always validates successfully), which will
get picked up if you do not provide a higher-priority instance yourself.
This trait provides an implicit function that will generate a ValueWrapper[W,V] for a case class of type
Wthat has a single member of typeV. This uses Shapeless to summon aGeneric[W, V :: HNil]to assist with the wrapping and unwrapping, so it will actually work with any typeWthat is record-like enough for Shapeless to handle.The
genWVfunction also takes an implicitValidator[W,V]that allows for some form of validation and manipulation of the value to be wrapped when constructing theWinstance.