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My reference is the correct compilation in the latest IntelliJ IDEA. The method newHashMap(Collection<? extends T>) in the type Reference is not applicable for the arguments (List<GenericsBug.TestClass>) --------Interface1.java-------- package com.generics; public interface Interface1 { void test(); } --------HasReference.java-------- package com.generics; public interface Interface2<T extends Interface1> { Reference<T> getRef(); } --------Reference.java-------- package com.generics; import java.io.Serializable; import java.util.Collection; import java.util.Collections; import java.util.HashMap; import java.util.Map; public class Reference<T extends Interface1> implements Interface1, Comparable<Reference<T>>, Serializable { @Override public int compareTo(Reference<T> o) { // TODO Auto-generated method stub return 0; } @Override public void test() { // TODO Auto-generated method stub } public static <T extends Interface1 & Interface2<T>> Map<Reference<T>, T> newHashMap( Collection<? extends T> items) { if ((items == null) || items.isEmpty()) { return Collections.emptyMap(); } Map<Reference<T>, T> idMap = new HashMap<>(items.size()); for (T item : items) { idMap.put(item.getRef(), item); } return idMap; } } --------GenericsBug.java-------- package com.generics; import java.util.Arrays; import java.util.Collection; import java.util.Map; import java.util.UUID; public class GenericsBug { private final TestClass testObj1 = new TestClass(); private final TestClass testObj2 = new TestClass(); private final TestClass testObj3 = new TestClass(); public void test() { Map<Reference<TestClass>, TestClass> map = Reference.newHashMap(Arrays.asList(testObj3, testObj2, testObj1)); } private static class TestClass implements Interface1, Interface2 { @Override public Reference getRef() { // TODO Auto-generated method stub return null; } @Override public void test() { // TODO Auto-generated method stub } } }
I ran into the same problem and created a much simpler test case: class Test { void test() { get(new Concrete()); } <T, C extends Base<T>> void get(C arg) {} static class Base<T> {} static class Concrete extends Base {} } It compiles fine in Java 7, but in Java 8+ it gives the following error: The method get(C) in the type Test is not applicable for the arguments (Test.Concrete)
This bug hasn't had any activity in quite some time. Maybe the problem got resolved, was a duplicate of something else, or became less pressing for some reason - or maybe it's still relevant but just hasn't been looked at yet. If you have further information on the current state of the bug, please add it. The information can be, for example, that the problem still occurs, that you still want the feature, that more information is needed, or that the bug is (for whatever reason) no longer relevant. -- The automated Eclipse Genie.
