type-alias-enum-variants-pass: harden; account for unit variants.

src/test/ui/type-alias-enum-variants/type-alias-enum-variants-pass.rs

@@ -1,30 +1,69 @@
 // run-pass
 
+// Check that it is possible to resolve, in the value namespace,
+// to an `enum` variant through a type alias. This includes `Self`.
+// Type qualified syntax `<Type>::Variant` also works when syntactically valid.
+
 #[derive(Debug, PartialEq, Eq)]
 enum Foo {
     Bar(i32),
     Baz { i: i32 },
+    Qux,
 }
 
 type FooAlias = Foo;
 type OptionAlias = Option<i32>;
 
+macro_rules! check_pat {
+    ($x:expr, $p:pat) => {
+        assert!(if let $p = $x { true } else { false });
+    };
+}
+
 impl Foo {
-    fn foo() -> Self {
-        Self::Bar(3)
+    fn bar() -> Self {
+        let x = Self::Bar(3);
+        assert_eq!(x, <Self>::Bar(3));
+        check_pat!(x, Self::Bar(3));
+        x
+    }
+
+    fn baz() -> Self {
+        let x = Self::Baz { i: 42 };
+        check_pat!(x, Self::Baz { i: 42 });
+        x
+    }
+
+    fn qux() -> Self {
+        let x = Self::Qux;
+        assert_eq!(x, <Self>::Qux);
+        check_pat!(x, Self::Qux);
+        check_pat!(x, <Self>::Qux);
+        x
     }
 }
 
 fn main() {
-    let t = FooAlias::Bar(1);
-    assert_eq!(t, Foo::Bar(1));
-    let t = FooAlias::Baz { i: 2 };
-    assert_eq!(t, Foo::Baz { i: 2 });
-    match t {
-        FooAlias::Bar(_i) => {}
-        FooAlias::Baz { i } => { assert_eq!(i, 2); }
-    }
-    assert_eq!(Foo::foo(), Foo::Bar(3));
+    let bar = Foo::Bar(1);
+    assert_eq!(bar, FooAlias::Bar(1));
+    assert_eq!(bar, <FooAlias>::Bar(1));
+    check_pat!(bar, FooAlias::Bar(1));
 
-    assert_eq!(OptionAlias::Some(4), Option::Some(4));
+    let baz = FooAlias::Baz { i: 2 };
+    assert_eq!(baz, Foo::Baz { i: 2 });
+    check_pat!(baz, FooAlias::Baz { i: 2 });
+
+    let qux = Foo::Qux;
+    assert_eq!(qux, FooAlias::Qux);
+    assert_eq!(qux, <FooAlias>::Qux);
+    check_pat!(qux, FooAlias::Qux);
+    check_pat!(qux, <FooAlias>::Qux);
+
+    assert_eq!(Foo::bar(), Foo::Bar(3));
+    assert_eq!(Foo::baz(), Foo::Baz { i: 42 });
+    assert_eq!(Foo::qux(), Foo::Qux);
+
+    let some = Option::Some(4);
+    assert_eq!(some, OptionAlias::Some(4));
+    check_pat!(some, OptionAlias::Some(4));
 }