// CS0462: `B.this[int]' cannot override inherited members `A<T>.this[int]' and `A<T>.this[T]' because they have the same signature when used in type `B' // Line: 12 abstract class A<T> { public abstract int this[T t] { set; } public virtual bool this [int a] { set { } } } class B : A<int> { public override int this [int a] { set {} } }