1 files changed, 57 insertions, 0 deletions
diff --git a/third_party/rust/derive_more/tests/is_variant.rs b/third_party/rust/derive_more/tests/is_variant.rs
new file mode 100644
index 0000000000..10876a40b3
--- /dev/null
+++ b/third_party/rust/derive_more/tests/is_variant.rs
@@ -0,0 +1,57 @@
+#![allow(dead_code)]
+
+#[macro_use]
+extern crate derive_more;
+
+#[derive(IsVariant)]
+enum Either<TLeft, TRight> {
+    Left(TLeft),
+    Right(TRight),
+}
+
+#[derive(IsVariant)]
+enum Maybe<T> {
+    Nothing,
+    Just(T),
+}
+
+#[derive(IsVariant)]
+enum Color {
+    RGB(u8, u8, u8),
+    CMYK { c: u8, m: u8, y: u8, k: u8 },
+}
+
+#[derive(IsVariant)]
+enum Nonsense<'a, T> {
+    Ref(&'a T),
+    NoRef,
+    #[is_variant(ignore)]
+    NoRefIgnored,
+}
+
+#[derive(IsVariant)]
+enum WithConstraints<T>
+where
+    T: Copy,
+{
+    One(T),
+    Two,
+}
+#[derive(IsVariant)]
+enum KitchenSink<'a, 'b, T1: Copy, T2: Clone>
+where
+    T2: Into<T1> + 'b,
+{
+    Left(&'a T1),
+    Right(&'b T2),
+    OwnBoth { left: T1, right: T2 },
+    Empty,
+    NeverMind(),
+    NothingToSeeHere {},
+}
+
+#[test]
+pub fn test_is_variant() {
+    assert!(Maybe::<()>::Nothing.is_nothing());
+    assert!(!Maybe::<()>::Nothing.is_just());
+}