com.google.errorprone.annotations.CompatibleWith Maven / Gradle / Ivy
/*
* Copyright 2016 The Error Prone 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.errorprone.annotations;
import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import java.util.Collection;
/**
* Declares that a parameter to a method must be "compatible with" one of the type parameters in the
* method's enclosing class, or on the method itself. "Compatible with" means that there can exist a
* "reference casting conversion" from one type to the other (JLS 5.5.1).
*
* For example, {@link Collection#contains} would be annotated as follows:
*
*
{@code
* interface Collection {
* boolean contains(@CompatibleWith("E") Object o);
* }
* }
*
* To indicate that invocations of {@link Collection#contains} must be passed an argument whose
* type is compatible with the generic type argument of the Collection instance:
*
*
{@code
* Collection stringCollection = ...;
* boolean shouldBeFalse = stringCollection.contains(42); // BUG! int isn't compatible with String
* }
*
* Note: currently, this annotation can't be used if the method overrides another method that has
* {@code @CompatibleWith} already present.
*/
@Documented
@Retention(RetentionPolicy.CLASS)
@Target(ElementType.PARAMETER)
public @interface CompatibleWith {
String value();
}