AK: Add FlyString::is_one_of for variadic string comparison

2 files changed, 22 insertions, 0 deletions

diff --git a/AK/FlyString.h b/AK/FlyString.h
index a2e68cef47..f6f09b2122 100644
--- a/AK/FlyString.h
+++ b/AK/FlyString.h
@@ -58,6 +58,12 @@ public:
     // Compare this FlyString against another string with ASCII caseless matching.
     [[nodiscard]] bool equals_ignoring_ascii_case(FlyString const&) const;
 
+    template<typename... Ts>
+    [[nodiscard]] ALWAYS_INLINE constexpr bool is_one_of(Ts... strings) const
+    {
+        return (... || this->operator==(forward<Ts>(strings)));
+    }
+
 private:
     // This will hold either the pointer to the Detail::StringData it represents or the raw bytes of
     // an inlined short string.
diff --git a/Tests/AK/TestFlyString.cpp b/Tests/AK/TestFlyString.cpp
index ff0cd0d5f7..dc182c2b8f 100644
--- a/Tests/AK/TestFlyString.cpp
+++ b/Tests/AK/TestFlyString.cpp
@@ -118,3 +118,19 @@ TEST_CASE(moved_fly_string_becomes_empty)
     EXPECT_EQ(fly1, "thisisdefinitelymorethan7bytes"sv);
     EXPECT_EQ(FlyString::number_of_fly_strings(), 1u);
 }
+
+TEST_CASE(is_one_of)
+{
+    auto foo = MUST(FlyString::from_utf8("foo"sv));
+    auto bar = MUST(FlyString::from_utf8("bar"sv));
+
+    EXPECT(foo.is_one_of(foo));
+    EXPECT(foo.is_one_of(foo, bar));
+    EXPECT(foo.is_one_of(bar, foo));
+    EXPECT(!foo.is_one_of(bar));
+
+    EXPECT(!bar.is_one_of("foo"sv));
+    EXPECT(bar.is_one_of("foo"sv, "bar"sv));
+    EXPECT(bar.is_one_of("bar"sv, "foo"sv));
+    EXPECT(bar.is_one_of("bar"sv));
+}