Added tests for enums & enum aliases with various combinations of generic args.

src/test/run-pass/enum-generic-args.rs

@@ -0,0 +1,34 @@
+#![feature(irrefutable_let_patterns)]
+#![feature(type_alias_enum_variants)]
+
+#![allow(irrefutable_let_patterns)]
+
+enum Enum<T> { Variant(T) }
+type Alias<T> = Enum<T>;
+type AliasFixed = Enum<()>;
+
+macro_rules! is_variant {
+    ($expr:expr) => (
+        assert!(if let Enum::Variant::<()>(_) = $expr { true } else { false },
+                "expr does not have correct type");
+    )
+}
+
+impl<T> Enum<T> {
+    fn foo() {
+        is_variant!(Self::Variant(()));
+    }
+}
+
+fn main() {
+    is_variant!(Enum::Variant(()));
+    is_variant!(Enum::Variant::<()>(()));
+    is_variant!(Enum::<()>::Variant(()));
+
+    is_variant!(Alias::Variant(()));
+    is_variant!(Alias::<()>::Variant(()));
+
+    is_variant!(AliasFixed::Variant(()));
+
+    Enum::<()>::foo();
+}

src/test/ui/enum-generic-args.rs

@@ -0,0 +1,35 @@
+#![feature(type_alias_enum_variants)]
+
+enum Enum<T> { Variant(T) }
+type Alias<T> = Enum<T>;
+type AliasFixed = Enum<()>;
+
+impl<T> Enum<T> {
+    fn foo() {
+        Self::Variant::<()>(());
+        //~^ ERROR type parameters are not allowed on this type [E0109]
+        Self::<()>::Variant(());
+        //~^ ERROR type parameters are not allowed on this type [E0109]
+        Self::<()>::Variant::<()>(());
+        //~^ ERROR type parameters are not allowed on this type [E0109]
+        //~^^ ERROR type parameters are not allowed on this type [E0109]
+    }
+}
+
+fn main() {
+    Enum::<()>::Variant::<()>(());
+    //~^ ERROR type parameters are not allowed on this type [E0109]
+
+    Alias::Variant::<()>(());
+    //~^ ERROR type parameters are not allowed on this type [E0109]
+    Alias::<()>::Variant::<()>(());
+    //~^ ERROR type parameters are not allowed on this type [E0109]
+
+    AliasFixed::Variant::<()>(());
+    //~^ ERROR type parameters are not allowed on this type [E0109]
+    AliasFixed::<()>::Variant(());
+    //~^ ERROR wrong number of type arguments: expected 0, found 1 [E0107]
+    AliasFixed::<()>::Variant::<()>(());
+    //~^ ERROR type parameters are not allowed on this type [E0109]
+    //~^^ ERROR wrong number of type arguments: expected 0, found 1 [E0107]
+}

src/test/ui/enum-generic-args.stderr

@@ -0,0 +1,70 @@
+error[E0109]: type parameters are not allowed on this type
+  --> $DIR/enum-generic-args.rs:9:25
+   |
+LL |         Self::Variant::<()>(());
+   |                         ^^ type parameter not allowed
+
+error[E0109]: type parameters are not allowed on this type
+  --> $DIR/enum-generic-args.rs:11:16
+   |
+LL |         Self::<()>::Variant(());
+   |                ^^ type parameter not allowed
+
+error[E0109]: type parameters are not allowed on this type
+  --> $DIR/enum-generic-args.rs:13:16
+   |
+LL |         Self::<()>::Variant::<()>(());
+   |                ^^ type parameter not allowed
+
+error[E0109]: type parameters are not allowed on this type
+  --> $DIR/enum-generic-args.rs:13:31
+   |
+LL |         Self::<()>::Variant::<()>(());
+   |                               ^^ type parameter not allowed
+
+error[E0109]: type parameters are not allowed on this type
+  --> $DIR/enum-generic-args.rs:20:27
+   |
+LL |     Enum::<()>::Variant::<()>(());
+   |                           ^^ type parameter not allowed
+
+error[E0109]: type parameters are not allowed on this type
+  --> $DIR/enum-generic-args.rs:23:22
+   |
+LL |     Alias::Variant::<()>(());
+   |                      ^^ type parameter not allowed
+
+error[E0109]: type parameters are not allowed on this type
+  --> $DIR/enum-generic-args.rs:25:28
+   |
+LL |     Alias::<()>::Variant::<()>(());
+   |                            ^^ type parameter not allowed
+
+error[E0109]: type parameters are not allowed on this type
+  --> $DIR/enum-generic-args.rs:28:27
+   |
+LL |     AliasFixed::Variant::<()>(());
+   |                           ^^ type parameter not allowed
+
+error[E0107]: wrong number of type arguments: expected 0, found 1
+  --> $DIR/enum-generic-args.rs:30:18
+   |
+LL |     AliasFixed::<()>::Variant(());
+   |                  ^^ unexpected type argument
+
+error[E0107]: wrong number of type arguments: expected 0, found 1
+  --> $DIR/enum-generic-args.rs:32:18
+   |
+LL |     AliasFixed::<()>::Variant::<()>(());
+   |                  ^^ unexpected type argument
+
+error[E0109]: type parameters are not allowed on this type
+  --> $DIR/enum-generic-args.rs:32:33
+   |
+LL |     AliasFixed::<()>::Variant::<()>(());
+   |                                 ^^ type parameter not allowed
+
+error: aborting due to 11 previous errors
+
+Some errors occurred: E0107, E0109.
+For more information about an error, try `rustc --explain E0107`.