From 3db14f182c4dce4d6ace923c291456e7d1249bc9 Mon Sep 17 00:00:00 2001
From: HMPerson1 <hmperson1@gmail.com>
Date: Wed, 24 Oct 2018 23:28:54 -0400
Subject: [PATCH] Check existential types in `use_self`

---
 clippy_lints/src/use_self.rs |  2 +-
 tests/ui/use_self.rs         | 14 ++++++++++++++
 tests/ui/use_self.stderr     |  8 +++++++-
 3 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/clippy_lints/src/use_self.rs b/clippy_lints/src/use_self.rs
index d770ea120..a8b7e8206 100644
--- a/clippy_lints/src/use_self.rs
+++ b/clippy_lints/src/use_self.rs
@@ -226,6 +226,6 @@ impl<'a, 'tcx> Visitor<'tcx> for UseSelfVisitor<'a, 'tcx> {
     }
 
     fn nested_visit_map<'this>(&'this mut self) -> NestedVisitorMap<'this, 'tcx> {
-        NestedVisitorMap::OnlyBodies(&self.cx.tcx.hir)
+        NestedVisitorMap::All(&self.cx.tcx.hir)
     }
 }
diff --git a/tests/ui/use_self.rs b/tests/ui/use_self.rs
index 6ebe8f16a..073d64d5a 100644
--- a/tests/ui/use_self.rs
+++ b/tests/ui/use_self.rs
@@ -205,3 +205,17 @@ mod issue2894 {
         }
     }
 }
+
+mod existential {
+    struct Foo;
+
+    impl Foo {
+        fn bad(foos: &[Self]) -> impl Iterator<Item=&Foo> {
+            foos.iter()
+        }
+
+        fn good(foos: &[Self]) -> impl Iterator<Item=&Self> {
+            foos.iter()
+        }
+    }
+}
diff --git a/tests/ui/use_self.stderr b/tests/ui/use_self.stderr
index 627fc3a97..b71c7a9a4 100644
--- a/tests/ui/use_self.stderr
+++ b/tests/ui/use_self.stderr
@@ -120,5 +120,11 @@ error: unnecessary structure name repetition
 119 |         fn mul(self, rhs: Bad) -> Bad {
     |                                   ^^^ help: use the applicable keyword: `Self`
 
-error: aborting due to 20 previous errors
+error: unnecessary structure name repetition
+   --> $DIR/use_self.rs:213:54
+    |
+213 |         fn bad(foos: &[Self]) -> impl Iterator<Item=&Foo> {
+    |                                                      ^^^ help: use the applicable keyword: `Self`
+
+error: aborting due to 21 previous errors