Files

30 lines
979 B
Java

import java.util.ArrayList;
import java.util.Collections;
class SortTest<R extends Comparable<R>> implements Comparable<SortTest<R>> {
R r;
public SortTest(R r) {
this.r = r;
}
public int compareTo(SortTest<R> o) {
return r.compareTo(o.r);
}
public static void main(String[] args) {
ArrayList<SortTest<?>> list = new ArrayList<SortTest<?>>();
SortTest<?> t1 = new SortTest<String>("");
list.add(t1);
SortTest<?> t2 = new SortTest<Integer>(0);
list.add(t2);
Collections.sort<error descr="'sort(java.util.List<T>)' in 'java.util.Collections' cannot be applied to '(java.util.ArrayList<SortTest<?>>)'">(list)</error>;
t1.compareTo<error descr="'compareTo(SortTest<capture<?>>)' in 'SortTest' cannot be applied to '(SortTest<capture<?>>)'">(t2)</error>;
//this should be OK
SortTest<?>[] arr = new SortTest<?>[0];
arr[0] = new SortTest<String>("");
}
}