| /* |
| * Copyright (C) 2021 The Guava Authors |
| * |
| * 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.common.cache; |
| |
| import static java.lang.annotation.ElementType.FIELD; |
| import static java.lang.annotation.ElementType.METHOD; |
| import static java.lang.annotation.ElementType.PARAMETER; |
| import static java.lang.annotation.RetentionPolicy.RUNTIME; |
| |
| import com.google.common.annotations.GwtCompatible; |
| import java.lang.annotation.Retention; |
| import java.lang.annotation.Target; |
| |
| /** |
| * Marks a "top-level" type-variable usage as the closest we can get to "non-nullable when |
| * non-nullable; nullable when nullable" (like the Android <a |
| * href="https://android.googlesource.com/platform/libcore/+/master/luni/src/main/java/libcore/util/NullFromTypeParam.java">{@code |
| * NullFromTypeParam}</a>). |
| * |
| * <p>Consumers of this annotation include: |
| * |
| * <ul> |
| * <li>Kotlin, for which it makes the type-variable usage (a) a Kotlin platform type when the type |
| * argument is non-nullable and (b) nullable when the type argument is nullable. We use this |
| * to "undo" {@link ElementTypesAreNonnullByDefault}. |
| * <li><a href="https://developers.google.com/j2objc">J2ObjC</a> |
| * <li>{@code NullPointerTester}, at least in the Android backport (where the type-use annotations |
| * {@code NullPointerTester} would need are not available) and in case of <a |
| * href="https://bugs.openjdk.java.net/browse/JDK-8202469">JDK-8202469</a> |
| * </ul> |
| * |
| */ |
| @GwtCompatible |
| @Retention(RUNTIME) |
| @Target({FIELD, METHOD, PARAMETER}) |
| @javax.annotation.meta.TypeQualifierNickname |
| @javax.annotation.Nonnull(when = javax.annotation.meta.When.UNKNOWN) |
| @interface ParametricNullness {} |