tupletest15.java

JAVA编程思想第四版英文原版习题答案. pdf原版的

// generics/TupleTest15.java
// TIJ4 Chapter Generics, Exercise 15, page 641
/* ... if you were to try to capture the result of f2() into a 
* paramterized TwoTuple, the compiler would issue a warning.
* Verify the previous statement.
*/
import net.mindview.util.*;
import static net.mindview.util.Tuple.*;

public class TupleTest15 {
	static TwoTuple<String,Integer> f() {
		return tuple("hi", 47);
	}
	static TwoTuple f2() { return tuple("hi", 47); }
	static ThreeTuple<Amphibian,String,Integer> g() {
		return tuple(new Amphibian(), "hi", 47);
	}
	static FourTuple<Vehicle,Amphibian,String,Integer> h() {
		return tuple(new Vehicle(), new Amphibian(), "hi", 47);
	}
	static FiveTuple<Vehicle,Amphibian,String,Integer,Double> k() {
		return tuple(new Vehicle(), new Amphibian(), "hi", 47,
		11.1);
	}
	public static void main(String[] args) {
		TwoTuple<String,Integer> ttsi = f();
		// compiler warning: unchecked conversion:
		TwoTuple<String,Integer> ttsi2 = f2();
		System.out.println(ttsi);
		System.out.println(f2());
		System.out.println(g());
		System.out.println(h());
		System.out.println(k());
	}
}