| package org.checkerframework.checker.nullness.qual; |
| |
| 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 org.checkerframework.framework.qual.InvisibleQualifier; |
| import org.checkerframework.framework.qual.SubtypeOf; |
| import org.checkerframework.framework.qual.TargetLocations; |
| import org.checkerframework.framework.qual.TypeUseLocation; |
| |
| /** |
| * The bottom type in the Map Key type system. Programmers should rarely write this type. |
| * |
| * <p>There are no values of this type (not even {@code null}). |
| * |
| * @checker_framework.manual #map-key-checker Map Key Checker |
| * @checker_framework.manual #bottom-type the bottom type |
| */ |
| @Documented |
| @Retention(RetentionPolicy.RUNTIME) |
| @Target({ElementType.TYPE_USE, ElementType.TYPE_PARAMETER}) |
| @TargetLocations({TypeUseLocation.EXPLICIT_LOWER_BOUND, TypeUseLocation.EXPLICIT_UPPER_BOUND}) |
| @InvisibleQualifier |
| @SubtypeOf(KeyFor.class) |
| public @interface KeyForBottom {} |