1 files changed, 53 insertions, 0 deletions
diff --git a/src/test/ui/generics/generic-default-type-params.rs b/src/test/ui/generics/generic-default-type-params.rs
new file mode 100644
index 000000000..afdd301fd
--- /dev/null
+++ b/src/test/ui/generics/generic-default-type-params.rs
@@ -0,0 +1,53 @@
+// run-pass
+struct Foo<A = (isize, char)> {
+    a: A
+}
+
+impl Foo<isize> {
+    fn bar_int(&self) -> isize {
+        self.a
+    }
+}
+
+impl Foo<char> {
+    fn bar_char(&self) -> char {
+        self.a
+    }
+}
+
+impl Foo {
+    fn bar(&self) {
+        let (i, c): (isize, char) = self.a;
+        assert_eq!(Foo { a: i }.bar_int(), i);
+        assert_eq!(Foo { a: c }.bar_char(), c);
+    }
+}
+
+impl<A: Clone> Foo<A> {
+    fn baz(&self) -> A {
+        self.a.clone()
+    }
+}
+
+fn default_foo(x: Foo) {
+    let (i, c): (isize, char) = x.a;
+    assert_eq!(i, 1);
+    assert_eq!(c, 'a');
+
+    x.bar();
+    assert_eq!(x.baz(), (1, 'a'));
+}
+
+#[derive(PartialEq, Debug)]
+struct BazHelper<T>(T);
+
+#[derive(PartialEq, Debug)]
+// Ensure that we can use previous type parameters in defaults.
+struct Baz<T, U = BazHelper<T>, V = Option<U>>(T, U, V);
+
+fn main() {
+    default_foo(Foo { a: (1, 'a') });
+
+    let x: Baz<bool> = Baz(true, BazHelper(false), Some(BazHelper(true)));
+    assert_eq!(x, Baz(true, BazHelper(false), Some(BazHelper(true))));
+}