1/*  Copyright (c) 2000-2006 hamcrest.org
2 */
3package org.hamcrest.core;
4
5import static org.hamcrest.core.IsNot.not;
6import org.hamcrest.Description;
7import org.hamcrest.Matcher;
8import org.hamcrest.Factory;
9import org.hamcrest.BaseMatcher;
10
11/**
12 * Is the value null?
13 */
14public class IsNull<T> extends BaseMatcher<T> {
15    public boolean matches(Object o) {
16        return o == null;
17    }
18
19    public void describeTo(Description description) {
20        description.appendText("null");
21    }
22
23    /**
24     * Matches if value is null.
25     */
26    @Factory
27    public static <T> Matcher<T> nullValue() {
28        return new IsNull<T>();
29    }
30
31    /**
32     * Matches if value is not null.
33     */
34    @Factory
35    public static <T> Matcher<T> notNullValue() {
36        return not(IsNull.<T>nullValue());
37    }
38
39    /**
40     * Matches if value is null. With type inference.
41     */
42    @Factory
43    public static <T> Matcher<T> nullValue(@SuppressWarnings("unused") Class<T> type) {
44        return nullValue();
45    }
46
47    /**
48     * Matches if value is not null. With type inference.
49     */
50    @Factory
51    public static <T> Matcher<T> notNullValue(@SuppressWarnings("unused") Class<T> type) {
52        return notNullValue();
53    }
54}
55
56