notselfbounded.java

来自「think in java 最新版本的源码」· Java 代码 · 共 22 行

//: generics/NotSelfBounded.java

public class NotSelfBounded<T> {
  T element;
  NotSelfBounded<T> set(T arg) {
    element = arg;
    return this;
  }
  T get() { return element; }
}

class A2 extends NotSelfBounded<A2> {}
class B2 extends NotSelfBounded<A2> {}

class C2 extends NotSelfBounded<C2> {
  C2 setAndGet(C2 arg) { set(arg); return get(); }
}	

class D2 {}
// Now this is OK:
class E2 extends NotSelfBounded<D2> {} ///:~