| // Copyright 2014 The Bazel Authors. All rights reserved. |
| // |
| // 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.devtools.build.xcode.util; |
| |
| import static com.google.common.base.Preconditions.checkNotNull; |
| |
| import com.google.common.base.Optional; |
| |
| import java.io.File; |
| import java.nio.file.Path; |
| import java.util.List; |
| import java.util.Set; |
| |
| /** |
| * Provides utility methods that make equality comparison type safe. The |
| * {@link Object#equals(Object)} method usually returns false when the other object is {@code null} |
| * or a different runtime class. These utility methods try to force each object to be of the same |
| * class (with the method signatures) and non-null (and throwing a {@link NullPointerException} if |
| * either one is null. |
| */ |
| public class Equaling { |
| private Equaling() { |
| throw new UnsupportedOperationException("static-only"); |
| } |
| |
| // Note that we always checkNotNull(b) on a separate line from a.equals(b). This is to make it so |
| // the stack trace will tell you exactly which reference is null. |
| |
| public static <T extends Value<T>> boolean of(Value<T> a, Value<T> b) { |
| checkNotNull(b); |
| return a.equals(b); |
| } |
| |
| public static boolean of(String a, String b) { |
| checkNotNull(b); |
| return a.equals(b); |
| } |
| |
| public static <T> boolean of(Optional<T> a, Optional<T> b) { |
| checkNotNull(b); |
| return a.equals(b); |
| } |
| |
| public static <T> boolean of(Set<T> a, Set<T> b) { |
| checkNotNull(b); |
| return a.equals(b); |
| } |
| |
| public static boolean of(File a, File b) { |
| checkNotNull(b); |
| return a.equals(b); |
| } |
| |
| public static boolean of(Path a, Path b) { |
| checkNotNull(b); |
| return a.equals(b); |
| } |
| |
| public static <T> boolean of(List<T> a, List<T> b) { |
| checkNotNull(b); |
| return a.equals(b); |
| } |
| |
| public static <T extends Enum<T>> boolean of(Enum<T> a, Enum<T> b) { |
| checkNotNull(b); |
| return a.equals(b); |
| } |
| } |