com.hazelcast.org.checkerframework.common.returnsreceiver.qual.This Maven / Gradle / Ivy
package com.hazelcast.org.checkerframework.common.returnsreceiver.qual;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;
import com.hazelcast.org.checkerframework.framework.qual.PolymorphicQualifier;
import com.hazelcast.org.checkerframework.framework.qual.TargetLocations;
import com.hazelcast.org.checkerframework.framework.qual.TypeUseLocation;
/**
* Write {@code @This} on the return type of a method that always returns its receiver ({@code
* this}). For example:
*
*
* class MyBuilder {
* @This MyBuilder setName(String name) {
* this.name = name;
* return this;
* }
* }
*
*
* Strictly speaking, this is a polymorphic annotation, but when you write it on a return type,
* the Returns Receiver Checker automatically adds it to the receiver, so the above method is
* equivalent to:
*
*
* @This MyBuilder setName(@This MyBuilder this, String name) {
* this.name = name;
* return this;
* }
*
*
* While it would be natural to make {@code @This} the default annotation for receivers, it leads
* to false positives warnings due to https://github.com/typetools/checker-framework/issues/2931,
* so this defaulting is currently elided.
*
* @checker_framework.manual #returns-receiver-checker Returns Receiver Checker
* @checker_framework.manual #qualifier-polymorphism Qualifier polymorphism
*/
@Retention(RetentionPolicy.RUNTIME)
@Target({ElementType.TYPE_USE, ElementType.TYPE_PARAMETER})
@PolymorphicQualifier
@TargetLocations({TypeUseLocation.RECEIVER, TypeUseLocation.RETURN})
public @interface This {}