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/*
* Copyright (C) 2002-2022 Sebastiano Vigna
*
* 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 it.unimi.dsi.fastutil.objects;
import java.util.Set;
/** An abstract class providing basic methods for sets implementing a type-specific interface.
*
* Note that the type-specific {@link Set} interface adds a type-specific {@code remove()}
* method, as it is no longer harmful for subclasses. Thus, concrete subclasses of this class
* must implement {@code remove()} (the {@code rem()} implementation of this
* class just delegates to {@code remove()}).
*/
public abstract class AbstractObjectSet extends AbstractObjectCollection implements Cloneable, ObjectSet {
protected AbstractObjectSet() {}
@Override
public abstract ObjectIterator iterator();
@Override
public boolean equals(final Object o) {
if (o == this) return true;
if (!(o instanceof Set)) return false;
Set> s = (Set>) o;
if (s.size() != size()) return false;
return containsAll(s);
}
/** Returns a hash code for this set.
*
* The hash code of a set is computed by summing the hash codes of
* its elements.
*
* @return a hash code for this set.
*/
@Override
public int hashCode() {
int h = 0, n = size();
ObjectIterator i = iterator();
K k;
while(n-- != 0) {
k = i.next(); // We need k because KEY2JAVAHASH() is a macro with repeated evaluation.
h += ( (k) == null ? 0 : (k).hashCode() );
}
return h;
}
}