| // Copyright 2014 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| package org.chromium.mojo.system; |
| |
| |
| /** |
| * A pair of object. |
| * |
| * @param <F> Type of the first element. |
| * @param <S> Type of the second element. |
| */ |
| public class Pair<F, S> { |
| |
| public final F first; |
| public final S second; |
| |
| /** |
| * Dedicated constructor. |
| * |
| * @param first the first element of the pair. |
| * @param second the second element of the pair. |
| */ |
| public Pair(F first, S second) { |
| this.first = first; |
| this.second = second; |
| } |
| |
| /** |
| * equals() that handles null values. |
| */ |
| private boolean equals(Object o1, Object o2) { |
| return o1 == null ? o2 == null : o1.equals(o2); |
| } |
| |
| /** |
| * @see Object#equals(Object) |
| */ |
| @Override |
| public boolean equals(Object o) { |
| if (!(o instanceof Pair)) { |
| return false; |
| } |
| Pair<?, ?> p = (Pair<?, ?>) o; |
| return equals(first, p.first) && equals(second, p.second); |
| } |
| |
| /** |
| * @see Object#hashCode() |
| */ |
| @Override |
| public int hashCode() { |
| return (first == null ? 0 : first.hashCode()) ^ (second == null ? 0 : second.hashCode()); |
| } |
| |
| /** |
| * Helper method for creating a pair. |
| * |
| * @param a the first element of the pair. |
| * @param b the second element of the pair. |
| * @return the pair containing a and b. |
| */ |
| public static <A, B> Pair<A, B> create(A a, B b) { |
| return new Pair<A, B>(a, b); |
| } |
| } |