public class MyGenericClass<T> where T:IComparable { }

class MyClassy<T, U>
where T : class
where U : struct
{
}

public class MyGenericClass <T> where T: IComparable, new()
{
// The following line is not possible without new() constraint:
         T item = new T();
}

interface MyI { }
class Dictionary<TKey,TVal>
where TKey: IComparable, IEnumerable
where TVal: MyI
{
public void Add(TKey key, TVal val)
{
}
}

public bool MyMethod<T>(T t) where T : IMyInterface { }

delegate T MyDelegate<T>() where T : new()