AK: Enable direct comparsion of Optional<T> and T

This patch introduces a new operator== to compare an Optional to its
contained type directly. If the Optional does not contain a value, the
comparison will always return false.

This also adds a test case for the new behavior as well as comparison
between Optional objects themselves.

1 files changed, 43 insertions, 0 deletions

diff --git a/Tests/AK/TestOptional.cpp b/Tests/AK/TestOptional.cpp
index 583d11f0eb..427046eab8 100644
--- a/Tests/AK/TestOptional.cpp
+++ b/Tests/AK/TestOptional.cpp
@@ -53,3 +53,46 @@ TEST_CASE(short_notation)
     EXPECT_EQ(value->length(), 3u);
     EXPECT_EQ(*value, "foo");
 }
+
+TEST_CASE(comparison_without_values)
+{
+    Optional<StringView> opt0;
+    Optional<StringView> opt1;
+    Optional<String> opt2;
+    EXPECT_EQ(opt0, opt1);
+    EXPECT_EQ(opt0, opt2);
+}
+
+TEST_CASE(comparison_with_values)
+{
+    Optional<StringView> opt0;
+    Optional<StringView> opt1 = "foo";
+    Optional<String> opt2 = "foo";
+    Optional<StringView> opt3 = "bar";
+    EXPECT_NE(opt0, opt1);
+    EXPECT_EQ(opt1, opt2);
+    EXPECT_NE(opt1, opt3);
+}
+
+TEST_CASE(comparison_to_underlying_types)
+{
+    Optional<String> opt0;
+    EXPECT_NE(opt0, String());
+    EXPECT_NE(opt0, "foo");
+
+    Optional<StringView> opt1 = "foo";
+    EXPECT_EQ(opt1, "foo");
+    EXPECT_NE(opt1, "bar");
+    EXPECT_EQ(opt1, String("foo"));
+}
+
+TEST_CASE(comparison_with_numeric_types)
+{
+    Optional<u8> opt0;
+    EXPECT_NE(opt0, 0);
+    Optional<u8> opt1 = 7;
+    EXPECT_EQ(opt1, 7);
+    EXPECT_EQ(opt1, 7.0);
+    EXPECT_EQ(opt1, 7u);
+    EXPECT_NE(opt1, -2);
+}