content: /*
   * Copyright (c) 1999, 2021, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  package openjdk.tools.javac.util;
  
  import java.util.Objects;
  
  /** A generic class for pairs.
   *
   *  <p><b>This is NOT part of any supported API.
   *  If you write code that depends on this, you do so at your own risk.
   *  This code and its internal interfaces are subject to change or
   *  deletion without notice.</b>
   */
  public class Pair<A, B> {
  
      public final A fst;
      public final B snd;
  
      public Pair(A fst, B snd) {
          this.fst = fst;
          this.snd = snd;
      }
  
      public String toString() {
          return "Pair[" + fst + "," + snd + "]";
      }
  
      public boolean equals(Object other) {
          return
              other instanceof Pair<?,?> &&
              Objects.equals(fst, ((Pair<?,?>)other).fst) &&
              Objects.equals(snd, ((Pair<?,?>)other).snd);
      }
  
      public int hashCode() {
          if (fst == null) return (snd == null) ? 0 : snd.hashCode() + 1;
          else if (snd == null) return fst.hashCode() + 2;
          else return fst.hashCode() * 17 + snd.hashCode();
      }
  
      public static <A,B> Pair<A,B> of(A a, B b) {
          return new Pair<>(a,b);
      }
  }
  