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Abstract types and Classmanifest
Tue, 2011-10-11, 13:01
Dear user,
I am meeting a recurrent problem with Scala.
I have written a base class with an abstract type,
such as type K<:AnyRef and an abstract method returning a List[K].
Inside my base class, I would need to do List.toArray, but the compiler produces the following output.
error: could not find implicit value for evidence parameter of type ClassManifest[CurveMockTest.this.K]
I tried to change the type K<:AnyRef:ClassManifest but that didn't work.
Can you please help me?
Best Regards
I am meeting a recurrent problem with Scala.
I have written a base class with an abstract type,
such as type K<:AnyRef and an abstract method returning a List[K].
Inside my base class, I would need to do List.toArray, but the compiler produces the following output.
error: could not find implicit value for evidence parameter of type ClassManifest[CurveMockTest.this.K]
I tried to change the type K<:AnyRef:ClassManifest but that didn't work.
Can you please help me?
Best Regards
Tue, 2011-10-11, 21:17
#2
Re: Re: Abstract types and Classmanifest
Dear Peter,
I am not using a generic parameter for the class, but an abstract type and that leads to the error....
Best Regards
2011/10/11 Sonnenschein <peter.empen@arcor.de>
I am not using a generic parameter for the class, but an abstract type and that leads to the error....
Best Regards
2011/10/11 Sonnenschein <peter.empen@arcor.de>
Hi Edmondo,
you are on the right track with Manifest. But
class T[K<:AnyRef:ClassManifest]
being working code it's difficult to tell you what you are missing.
Here again, full, boiled-down code is advisable.
Peter
Tue, 2011-10-11, 21:47
#3
Re: Abstract types and Classmanifest
Sorry, I have missunderstood. Your problem is:
trait T{
type K<:AnyRef
def list: List[K]
def array=list.toArray
}
Try instead:
def array[X>:K:Manifest]=list.toArray[X]
Peter
Hi Edmondo,
you are on the right track with Manifest. But
class T[K<:AnyRef:ClassManifest]
being working code it's difficult to tell you what you are missing.
Here again, full, boiled-down code is advisable.
Peter