public interface IEntity {}

public interface IEntityEvaluatorInput<out TEntity> where TEntity : IEntity

{

    public TEntity Entity { get; }

}

public delegate bool EntityEvaluator<in TEvaluatorInput>(TEvaluatorInput input) where TEvaluatorInput: IEntityEvaluatorInput<IEntity>;

public class RowEditingConfigEvaluatorInput<TEntity> : IEntityEvaluatorInput<TEntity> where TEntity : IEntity

{

    public TEntity Entity { get; }

    public RowEditingConfigEvaluatorInput(TEntity entity)

    {

        Entity = entity;

    }

}

​

​

public class MyEntity: IEntity 

{

   public string MyProperty {get;set;}

}

​

​

public class Program

{

    public static void Main()

    {

        EntityEvaluator<IEntityEvaluatorInput<IEntity>> evaluator1 = delegate(IEntityEvaluatorInput<IEntity> input) { return ((MyEntity)input.Entity).MyProperty != null; };

        EntityEvaluator<IEntityEvaluatorInput<IEntity>> evaluator2 = delegate(IEntityEvaluatorInput<MyEntity> input) { return input.Entity.MyProperty != null; };

        EntityEvaluator<IEntityEvaluatorInput<IEntity>> evaluator3 = delegate(RowEditingConfigEvaluatorInput<MyEntity> input) { return input.Entity.MyProperty != null; };

    }

}

​