needless-lifetime / pr remarks

Author: tnielens

clippy_lints/src/lifetimes.rs

@@ -383,6 +383,7 @@ impl<'a, 'tcx> Visitor<'tcx> for RefVisitor<'a, 'tcx> {
                 let mut sub_visitor = RefVisitor::new(self.cx);
                 sub_visitor.visit_fn_decl(decl);
                 self.nested_elision_site_lts.append(&mut sub_visitor.all_lts());
+                return;
             },
             TyKind::TraitObject(bounds, ref lt) => {
                 if !lt.is_elided() {

tests/ui/needless_lifetimes.rs

@@ -336,9 +336,25 @@ mod nested_elision_sites {
         |i| i
     }
     // lint
-    fn pointer_fn_elidable<'a>(f: fn(&i32) -> &i32, i: &'a i32) -> &'a i32 {
+    fn pointer_fn_elidable<'a>(i: &'a i32, f: fn(&i32) -> &i32) -> &'a i32 {
         f(i)
     }
+
+    // don't lint
+    fn nested_fn_pointer_1<'a>(_: &'a i32) -> fn(fn(&'a i32) -> &'a i32) -> i32 {
+        |f| 42
+    }
+    fn nested_fn_pointer_2<'a>(_: &'a i32) -> impl Fn(fn(&'a i32)) {
+        |f| ()
+    }
+
+    // lint
+    fn nested_fn_pointer_3<'a>(_: &'a i32) -> fn(fn(&i32) -> &i32) -> i32 {
+        |f| 42
+    }
+    fn nested_fn_pointer_4<'a>(_: &'a i32) -> impl Fn(fn(&i32)) {
+        |f| ()
+    }
 }
 
 fn main() {}

tests/ui/needless_lifetimes.stderr

@@ -132,5 +132,23 @@ error: explicit lifetimes given in parameter types where they could be elided (o
 LL |     fn where_clause_elidadable<'a, T>(i: &'a i32, f: T) -> &'a i32
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-error: aborting due to 22 previous errors
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
+  --> $DIR/needless_lifetimes.rs:339:5
+   |
+LL |     fn pointer_fn_elidable<'a>(i: &'a i32, f: fn(&i32) -> &i32) -> &'a i32 {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
+  --> $DIR/needless_lifetimes.rs:352:5
+   |
+LL |     fn nested_fn_pointer_3<'a>(_: &'a i32) -> fn(fn(&i32) -> &i32) -> i32 {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: explicit lifetimes given in parameter types where they could be elided (or replaced with `'_` if needed by type declaration)
+  --> $DIR/needless_lifetimes.rs:355:5
+   |
+LL |     fn nested_fn_pointer_4<'a>(_: &'a i32) -> impl Fn(fn(&i32)) {
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 25 previous errors