Description Emilian Abadjiev 2006-06-18 04:29:56 EDT

It seems that there is a problem with generic methods that are covariant and the generic type information is erased. I noticed that Eclipse 3.1.2 cannot event compile java code with generic and methods that have covariant return type. The example bellow demonstrates the problem:

public class RootClass<Y extends Object> {

	public static <T extends Object> RootClass<T> make(Class<T> clazz) {
		return new RootClass<T>();
	}

	public static Object makeObject() {
		return null;
	}
}

public class ChildClass<Y extends String> extends RootClass<Y> {

	public static <T extends String> ChildClass<T> make(Class<T> clazz) {
		return new ChildClass<T>();
	}

	public static void main(String[] args) throws Exception {
		ChildClass.make(String.class); // doesn't work in Eclipse 3.1
		ChildClass.make(getClazz()); // doesn't work in Eclipse 3.2
		ChildClass.make(getClazz().newInstance().getClass()); // works in Eclipse 3.2
	}

	public static Class getClazz() {
		return String.class;
	}
	
}