Is there a generic type-constraint for "where NOT derived from"?
c#, generics
Solution
You could use something like the following:
public interface IFooGenerator
{
Foo GenerateFoo();
}
interface ISerialFooGenerator : IFooGenerator { }
interface IParallelFooGenerator : IFooGenerator { }
public class FooGenerator : ISerialFooGenerator
{
public Foo GenerateFoo()
{
//TODO
return null;
}
}
public class ParallelFooGenerator<T> : IParallelFooGenerator
where T : ISerialFooGenerator, new()
{
public Foo GenerateFoo()
{
//TODO
return null;
}
}
Problem
We can specify a "derived from" constraint on generic type parameters like this: ``` class Bar<T> where T : IFooGenerator ``` Is there a way to specify NOT derived from? My use-case: I have a bunch of `FooGenerator`s that are parallelizable, with the same parallelization code for each, but we don't want them to always be parallelized. ``` public class FooGenerator : IFooGenerator { public Foo GenerateFoo() { ... } } ``` Thus, I create a generic container class for generating Foo in parallel: ``` public class ParallelFooGenerator<T> : IFooGenerator where T : IFooGenerator { public Foo GenerateFoo() { //Call T.GenerateFoo() a bunch in parallel } } ``` Since I want `FooGenerator` and `ParallelFooGenerator<FooGenerator>` to be interchangeable, I make `ParallelFooGenerator : IFooGenerator`. However, I clearly don't want `ParallelFooGenerator<ParallelFooGenerator>` to be legal. So, as an auxiliary question, is there perhaps a better way to design this if "not derived from" constraints are impossible?