1 files changed, 59 insertions, 0 deletions
diff --git a/src/test/ui/type-alias-enum-variants/enum-variant-generic-args-pass.rs b/src/test/ui/type-alias-enum-variants/enum-variant-generic-args-pass.rs
new file mode 100644
index 000000000..0aa644db0
--- /dev/null
+++ b/src/test/ui/type-alias-enum-variants/enum-variant-generic-args-pass.rs
@@ -0,0 +1,59 @@
+// run-pass
+
+// Check that resolving, in the value namespace, to an `enum` variant
+// through a type alias is well behaved in the presence of generics.
+// We check for situations with:
+// 1. a generic type `Alias<T>`, we can type-apply `Alias` when referring to a variant.
+// 2. a monotype `AliasFixed` of generic `Enum<T>`, we can refer to variants
+//    and the type-application of `T` in `AliasFixed` is kept.
+
+#![allow(irrefutable_let_patterns)]
+
+enum Enum<T> { TSVariant(#[allow(unused_tuple_struct_fields)] T), SVariant { _v: T }, UVariant }
+type Alias<T> = Enum<T>;
+type AliasFixed = Enum<()>;
+
+macro_rules! is_variant {
+    (TSVariant, $expr:expr) => (is_variant!(@check TSVariant, (_), $expr));
+    (SVariant, $expr:expr) => (is_variant!(@check SVariant, { _v: _ }, $expr));
+    (UVariant, $expr:expr) => (is_variant!(@check UVariant, {}, $expr));
+    (@check $variant:ident, $matcher:tt, $expr:expr) => (
+        assert!(if let Enum::$variant::<()> $matcher = $expr { true } else { false },
+                "expr does not have correct type");
+    );
+}
+
+fn main() {
+    // Tuple struct variant
+
+    is_variant!(TSVariant, Enum::TSVariant(()));
+    is_variant!(TSVariant, Enum::TSVariant::<()>(()));
+    is_variant!(TSVariant, Enum::<()>::TSVariant(()));
+
+    is_variant!(TSVariant, Alias::TSVariant(()));
+    is_variant!(TSVariant, Alias::<()>::TSVariant(()));
+
+    is_variant!(TSVariant, AliasFixed::TSVariant(()));
+
+    // Struct variant
+
+    is_variant!(SVariant, Enum::SVariant { _v: () });
+    is_variant!(SVariant, Enum::SVariant::<()> { _v: () });
+    is_variant!(SVariant, Enum::<()>::SVariant { _v: () });
+
+    is_variant!(SVariant, Alias::SVariant { _v: () });
+    is_variant!(SVariant, Alias::<()>::SVariant { _v: () });
+
+    is_variant!(SVariant, AliasFixed::SVariant { _v: () });
+
+    // Unit variant
+
+    is_variant!(UVariant, Enum::UVariant);
+    is_variant!(UVariant, Enum::UVariant::<()>);
+    is_variant!(UVariant, Enum::<()>::UVariant);
+
+    is_variant!(UVariant, Alias::UVariant);
+    is_variant!(UVariant, Alias::<()>::UVariant);
+
+    is_variant!(UVariant, AliasFixed::UVariant);
+}