From db32a2e4211f9444ef4f10b633e400d27ed2662e Mon Sep 17 00:00:00 2001
From: Florian Diebold <flodiebold@gmail.com>
Date: Fri, 10 Apr 2020 22:05:46 +0200
Subject: Implement inline associated type bounds

Like `Iterator<Item: SomeTrait>`.

This is an unstable feature, but it's used in the standard library e.g. in the
definition of Flatten, so we can't get away with not implementing it :)
---
 crates/ra_hir_ty/src/tests/traits.rs | 47 ++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

(limited to 'crates/ra_hir_ty/src/tests')

diff --git a/crates/ra_hir_ty/src/tests/traits.rs b/crates/ra_hir_ty/src/tests/traits.rs
index 22ae6ca90..53461bdbb 100644
--- a/crates/ra_hir_ty/src/tests/traits.rs
+++ b/crates/ra_hir_ty/src/tests/traits.rs
@@ -1923,6 +1923,53 @@ fn test<T, U>() where T: Trait<U::Item>, U: Trait<T::Item> {
     assert_eq!(t, "{unknown}");
 }
 
+#[test]
+fn inline_assoc_type_bounds_1() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Iterator {
+    type Item;
+}
+trait OtherTrait<T> {
+    fn foo(&self) -> T;
+}
+
+// workaround for Chalk assoc type normalization problems
+pub struct S<T>;
+impl<T: Iterator> Iterator for S<T> {
+    type Item = <T as Iterator>::Item;
+}
+
+fn test<I: Iterator<Item: OtherTrait<u32>>>() {
+    let x: <S<I> as Iterator>::Item;
+    x.foo()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "u32");
+}
+
+#[test]
+fn inline_assoc_type_bounds_2() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Iterator {
+    type Item;
+}
+
+fn test<I: Iterator<Item: Iterator<Item = u32>>>() {
+    let x: <<I as Iterator>::Item as Iterator>::Item;
+    x<|>;
+}
+"#,
+    );
+    // assert_eq!(t, "u32");
+    // doesn't currently work, Chalk #234
+    assert_eq!(t, "{unknown}");
+}
+
 #[test]
 fn unify_impl_trait() {
     assert_snapshot!(
-- 
cgit v1.2.3


From d88d67819b3f052422ad3f024e44ad73dde1630b Mon Sep 17 00:00:00 2001
From: Florian Diebold <flodiebold@gmail.com>
Date: Sun, 12 Apr 2020 12:29:03 +0200
Subject: Handle `Self::Type` in trait definitions when referring to own
 associated type

It was implemented for other generic parameters for the trait, but not for `Self`.
---
 crates/ra_hir_ty/src/tests/regression.rs |  3 +--
 crates/ra_hir_ty/src/tests/traits.rs     | 26 +++++++++++++++++++++++++-
 2 files changed, 26 insertions(+), 3 deletions(-)

(limited to 'crates/ra_hir_ty/src/tests')

diff --git a/crates/ra_hir_ty/src/tests/regression.rs b/crates/ra_hir_ty/src/tests/regression.rs
index 3402e0cb5..d69115a2f 100644
--- a/crates/ra_hir_ty/src/tests/regression.rs
+++ b/crates/ra_hir_ty/src/tests/regression.rs
@@ -451,8 +451,7 @@ pub mod str {
 "#,
     );
 
-    // should be Option<char>, but currently not because of Chalk ambiguity problem
-    assert_eq!("(Option<{unknown}>, Option<{unknown}>)", super::type_at_pos(&db, pos));
+    assert_eq!("(Option<char>, Option<char>)", super::type_at_pos(&db, pos));
 }
 
 #[test]
diff --git a/crates/ra_hir_ty/src/tests/traits.rs b/crates/ra_hir_ty/src/tests/traits.rs
index 22ae6ca90..d088bf309 100644
--- a/crates/ra_hir_ty/src/tests/traits.rs
+++ b/crates/ra_hir_ty/src/tests/traits.rs
@@ -1803,7 +1803,7 @@ fn test<T, U>() where T::Item: Trait2, T: Trait<U::Item>, U: Trait<()> {
 }
 
 #[test]
-fn unselected_projection_on_trait_self() {
+fn unselected_projection_on_impl_self() {
     assert_snapshot!(infer(
         r#"
 //- /main.rs
@@ -1843,6 +1843,30 @@ impl Trait for S2 {
     "###);
 }
 
+#[test]
+fn unselected_projection_on_trait_self() {
+    let t = type_at(
+        r#"
+//- /main.rs
+trait Trait {
+    type Item;
+
+    fn f(&self) -> Self::Item { loop {} }
+}
+
+struct S;
+impl Trait for S {
+    type Item = u32;
+}
+
+fn test() {
+    S.f()<|>;
+}
+"#,
+    );
+    assert_eq!(t, "u32");
+}
+
 #[test]
 fn trait_impl_self_ty() {
     let t = type_at(
-- 
cgit v1.2.3