/*
* Copyright (C) 2012 The Guava Authors
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.common.collect;
import java.util.Comparator;
import java.util.TreeMap;
/**
* GWT emulated version of {@link EmptyImmutableSortedMap}.
*
* @author Chris Povirk
*/
final class EmptyImmutableSortedMap<K, V> extends ImmutableSortedMap<K, V> {
private EmptyImmutableSortedMap(Comparator<? super K> comparator) {
super(new TreeMap<K, V>(comparator), comparator);
}
@SuppressWarnings("unchecked")
private static final ImmutableSortedMap<Object, Object> NATURAL_EMPTY_MAP =
new EmptyImmutableSortedMap<Object, Object>(NATURAL_ORDER);
static <K, V> ImmutableSortedMap<K, V> forComparator(Comparator<? super K> comparator) {
if (comparator == NATURAL_ORDER) {
return (ImmutableSortedMap) NATURAL_EMPTY_MAP;
}
return new EmptyImmutableSortedMap<K, V>(comparator);
}
}