1 /*******************************************************************************
2 * Copyright (c) 2007, 2010 Association for Decentralized Information Management
4 * All rights reserved. This program and the accompanying materials
5 * are made available under the terms of the Eclipse Public License v1.0
6 * which accompanies this distribution, and is available at
7 * http://www.eclipse.org/legal/epl-v10.html
10 * VTT Technical Research Centre of Finland - initial API and implementation
11 *******************************************************************************/
12 package org.simantics.utils.datastructures;
16 * A generic Pair (2-tuple) structure for containing two object instances of
19 * @param <T1> type of first element
20 * @param <T2> type of second element
22 public final class FirstIdentityPair<T1, T2> implements Comparable<FirstIdentityPair<T1, T2>> {
23 public final T1 first;
24 public final T2 second;
25 private final int hash;
27 public static <T1, T2> FirstIdentityPair<T1, T2> make(T1 t1, T2 t2) {
28 return new FirstIdentityPair<T1, T2>(t1, t2);
31 public FirstIdentityPair(T1 first, T2 second) {
32 //assert(first != null);
33 //assert(second != null);
37 this.hash = makeHash();
41 public boolean equals(Object obj) {
44 if (!(obj.getClass().equals(this.getClass())))
46 FirstIdentityPair<?, ?> other = (FirstIdentityPair<?, ?>) obj;
47 if (other.first != first && (other.first == null || !other.first.equals(first)))
53 public int hashCode() {
58 public String toString() {
59 return "<"+first+", "+second+">";
62 private int makeHash() {
63 return (first == null ? 0 : first.hashCode());
67 public int compareTo(FirstIdentityPair<T1, T2> arg0) {
68 return hash - arg0.hash;