Warn about hidden_lifetimes_in_output_paths by default

shepmaster · shepmaster · commit d12e7b06a924 · 2025-04-02T11:56:03.000-04:00
diff --git a/compiler/rustc_lint/src/lifetime_style.rs b/compiler/rustc_lint/src/lifetime_style.rs
@@ -136,7 +136,7 @@ declare_lint! {
     ///
     /// [placeholder lifetime]: https://doc.rust-lang.org/reference/lifetime-elision.html#lifetime-elision-in-functions
     pub HIDDEN_LIFETIMES_IN_OUTPUT_PATHS,
-    Allow,
+    Warn,
     "hidden lifetime parameters in types in function return values are deprecated"
 }
 
diff --git a/tests/ui/associated-types/associated-types-impl-redirect.rs b/tests/ui/associated-types/associated-types-impl-redirect.rs
@@ -21,7 +21,7 @@ trait Iterator {
 }
 
 trait IteratorExt: Iterator + Sized {
-    fn by_ref(&mut self) -> ByRef<Self> {
+    fn by_ref(&mut self) -> ByRef<'_, Self> {
         ByRef(self)
     }
 }
diff --git a/tests/ui/associated-types/associated-types-normalize-in-bounds-ufcs.rs b/tests/ui/associated-types/associated-types-normalize-in-bounds-ufcs.rs
@@ -21,11 +21,11 @@ trait SliceExt2 {
 impl<T> SliceExt2 for [T] {
     type Item = T;
 
-    fn split2<P>(&self, pred: P) -> Splits<T, P> where P: FnMut(&T) -> bool {
+    fn split2<P>(&self, pred: P) -> Splits<'_, T, P> where P: FnMut(&T) -> bool {
         loop {}
     }
 
-    fn splitn2<P>(&self, n: u32, pred: P) -> SplitsN<Splits<T, P>> where P: FnMut(&T) -> bool {
+    fn splitn2<P>(&self, n: u32, pred: P) -> SplitsN<Splits<'_, T, P>> where P: FnMut(&T) -> bool {
         SliceExt2::split2(self, pred);
         loop {}
     }
diff --git a/tests/ui/associated-types/associated-types-normalize-in-bounds.rs b/tests/ui/associated-types/associated-types-normalize-in-bounds.rs
@@ -21,11 +21,17 @@ trait SliceExt2 {
 impl<T> SliceExt2 for [T] {
     type Item = T;
 
-    fn split2<P>(&self, pred: P) -> Splits<T, P> where P: FnMut(&T) -> bool {
+    fn split2<P>(&self, pred: P) -> Splits<'_, T, P>
+    where
+        P: FnMut(&T) -> bool,
+    {
         loop {}
     }
 
-    fn splitn2<P>(&self, n: usize, pred: P) -> SplitsN<Splits<T, P>> where P: FnMut(&T) -> bool {
+    fn splitn2<P>(&self, n: usize, pred: P) -> SplitsN<Splits<'_, T, P>>
+    where
+        P: FnMut(&T) -> bool,
+    {
         self.split2(pred);
         loop {}
     }
diff --git a/tests/ui/associated-types/associated-types-where-clause-impl-ambiguity.rs b/tests/ui/associated-types/associated-types-where-clause-impl-ambiguity.rs
@@ -20,7 +20,7 @@ trait Iterator {
 }
 
 trait IteratorExt: Iterator + Sized {
-    fn by_ref(&mut self) -> ByRef<Self> {
+    fn by_ref(&mut self) -> ByRef<'_, Self> {
         ByRef(self)
     }
 }
diff --git a/tests/ui/associated-types/cache/elision.rs b/tests/ui/associated-types/cache/elision.rs
@@ -1,3 +1,5 @@
+#![allow(hidden_lifetimes_in_output_paths)]
+
 // Check that you are allowed to implement using elision but write
 // trait without elision (a bug in this cropped up during
 // bootstrapping, so this is a regression test).
diff --git a/tests/ui/associated-types/project-defer-unification.rs b/tests/ui/associated-types/project-defer-unification.rs
@@ -50,7 +50,7 @@ where P: Pixel + 'static,
         loop { }
     }
 
-    pub fn pixels_mut(&mut self) -> PixelsMut<P> {
+    pub fn pixels_mut(&mut self) -> PixelsMut<'_, P> {
         loop { }
     }
 }
diff --git a/tests/ui/borrowck/copy-suggestion-region-vid.fixed b/tests/ui/borrowck/copy-suggestion-region-vid.fixed
@@ -7,7 +7,7 @@ pub struct HelperStruct<'n> {
 }
 
 impl DataStruct {
-    pub fn f(&self) -> HelperStruct {
+    pub fn f(&self) -> HelperStruct<'_> {
         let helpers = [vec![], vec![]];
 
         HelperStruct { helpers: helpers.clone(), is_empty: helpers[0].is_empty() }
diff --git a/tests/ui/borrowck/copy-suggestion-region-vid.rs b/tests/ui/borrowck/copy-suggestion-region-vid.rs
@@ -7,7 +7,7 @@ pub struct HelperStruct<'n> {
 }
 
 impl DataStruct {
-    pub fn f(&self) -> HelperStruct {
+    pub fn f(&self) -> HelperStruct<'_> {
         let helpers = [vec![], vec![]];
 
         HelperStruct { helpers, is_empty: helpers[0].is_empty() }
diff --git a/tests/ui/const-generics/type-dependent/issue-71348.full.stderr b/tests/ui/const-generics/type-dependent/issue-71348.full.stderr
diff --git a/tests/ui/const-generics/type-dependent/issue-71348.min.stderr b/tests/ui/const-generics/type-dependent/issue-71348.min.stderr
@@ -17,7 +17,7 @@ LL + #![feature(unsized_const_params)]
 error: `&'static str` is forbidden as the type of a const generic parameter
   --> $DIR/issue-71348.rs:18:25
    |
-LL |     fn ask<'a, const N: &'static str>(&'a self) -> &'a <Self as Get<N>>::Target
+LL |     fn ask<'a, const N: &'static str>(&'a self) -> &'a <Self as Get<'a, N>>::Target
    |                         ^^^^^^^^^^^^
    |
    = note: the only supported types are integers, `bool`, and `char`
diff --git a/tests/ui/const-generics/type-dependent/issue-71348.rs b/tests/ui/const-generics/type-dependent/issue-71348.rs
@@ -15,9 +15,8 @@ trait Get<'a, const N: &'static str> {
 }
 
 impl Foo {
-    fn ask<'a, const N: &'static str>(&'a self) -> &'a <Self as Get<N>>::Target
+    fn ask<'a, const N: &'static str>(&'a self) -> &'a <Self as Get<'a, N>>::Target
     //[min]~^ ERROR `&'static str` is forbidden as the type of a const generic parameter
-    //[full]~^^ WARNING lifetime flowing from input to output with different syntax
     where
         Self: Get<'a, N>,
     {
diff --git a/tests/ui/drop/drop-order-comparisons.e2021.fixed b/tests/ui/drop/drop-order-comparisons.e2021.fixed
@@ -548,7 +548,7 @@ impl Events {
         Ok(LogDrop(self, m))
     }
     /// Return an `Err` value that logs its drop.
-    fn err(&self, m: u64) -> Result<LogDrop, LogDrop> {
+    fn err(&self, m: u64) -> Result<LogDrop<'_>, LogDrop<'_>> {
         Err(LogDrop(self, m))
     }
     /// Log an event.
diff --git a/tests/ui/drop/drop-order-comparisons.rs b/tests/ui/drop/drop-order-comparisons.rs
@@ -548,7 +548,7 @@ impl Events {
         Ok(LogDrop(self, m))
     }
     /// Return an `Err` value that logs its drop.
-    fn err(&self, m: u64) -> Result<LogDrop, LogDrop> {
+    fn err(&self, m: u64) -> Result<LogDrop<'_>, LogDrop<'_>> {
         Err(LogDrop(self, m))
     }
     /// Log an event.
diff --git a/tests/ui/drop/drop_order.rs b/tests/ui/drop/drop_order.rs
@@ -22,11 +22,11 @@ impl Drop for LoudDrop<'_> {
 }
 
 impl DropOrderCollector {
-    fn option_loud_drop(&self, n: u32) -> Option<LoudDrop> {
+    fn option_loud_drop(&self, n: u32) -> Option<LoudDrop<'_>> {
         Some(LoudDrop(self, n))
     }
 
-    fn loud_drop(&self, n: u32) -> LoudDrop {
+    fn loud_drop(&self, n: u32) -> LoudDrop<'_> {
         LoudDrop(self, n)
     }
 
diff --git a/tests/ui/drop/drop_order_if_let_rescope.rs b/tests/ui/drop/drop_order_if_let_rescope.rs
@@ -20,7 +20,7 @@ impl Drop for LoudDrop<'_> {
 }
 
 impl DropOrderCollector {
-    fn option_loud_drop(&self, n: u32) -> Option<LoudDrop> {
+    fn option_loud_drop(&self, n: u32) -> Option<LoudDrop<'_>> {
         Some(LoudDrop(self, n))
     }
 
diff --git a/tests/ui/drop/issue-2735-2.rs b/tests/ui/drop/issue-2735-2.rs
@@ -14,7 +14,7 @@ impl<'a> Drop for defer<'a> {
     }
 }
 
-fn defer(b: &Cell<bool>) -> defer {
+fn defer(b: &Cell<bool>) -> defer<'_> {
     defer {
         b: b
     }
diff --git a/tests/ui/drop/issue-2735-3.rs b/tests/ui/drop/issue-2735-3.rs
@@ -14,7 +14,7 @@ impl<'a> Drop for defer<'a> {
     }
 }
 
-fn defer(b: &Cell<bool>) -> defer {
+fn defer(b: &Cell<bool>) -> defer<'_> {
     defer {
         b: b
     }
diff --git a/tests/ui/drop/issue-979.rs b/tests/ui/drop/issue-979.rs
@@ -13,7 +13,7 @@ impl<'a> Drop for r<'a> {
     }
 }
 
-fn r(b: &Cell<isize>) -> r {
+fn r(b: &Cell<isize>) -> r<'_> {
     r {
         b: b
     }
diff --git a/tests/ui/drop/tail-expr-drop-order.rs b/tests/ui/drop/tail-expr-drop-order.rs
@@ -28,11 +28,11 @@ impl Drop for LoudDrop<'_> {
 }
 
 impl DropOrderCollector {
-    fn option_loud_drop(&self, n: u32) -> Option<LoudDrop> {
+    fn option_loud_drop(&self, n: u32) -> Option<LoudDrop<'_>> {
         Some(LoudDrop(self, n))
     }
 
-    fn loud_drop(&self, n: u32) -> LoudDrop {
+    fn loud_drop(&self, n: u32) -> LoudDrop<'_> {
         LoudDrop(self, n)
     }
 
diff --git a/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/issue-62529-1.rs b/tests/ui/higher-ranked/trait-bounds/normalize-under-binder/issue-62529-1.rs
@@ -25,7 +25,7 @@ where
 
 impl<T: 'static> Inject for RefMutFamily<T> {
     type I = Self;
-    fn inject(_: &()) -> <Self::I as FamilyLt>::Out {
+    fn inject(_: &()) -> <Self::I as FamilyLt<'_>>::Out {
         unimplemented!()
     }
 }
diff --git a/tests/ui/issues/issue-2502.rs b/tests/ui/issues/issue-2502.rs
@@ -14,7 +14,7 @@ impl<'a> font<'a> {
     }
 }
 
-fn font(fontbuf: &Vec<u8> ) -> font {
+fn font(fontbuf: &Vec<u8> ) -> font<'_> {
     font {
         fontbuf: fontbuf
     }
diff --git a/tests/ui/issues/issue-42552.rs b/tests/ui/issues/issue-42552.rs
@@ -1,7 +1,7 @@
 //@ run-pass
 // Regression test for an obscure issue with the projection cache.
 
-fn into_iter<I: Iterator>(a: &I) -> Groups<I> {
+fn into_iter<I: Iterator>(a: &I) -> Groups<'_, I> {
     Groups { _a: a }
 }
 
diff --git a/tests/ui/issues/issue-47703-1.rs b/tests/ui/issues/issue-47703-1.rs
@@ -13,7 +13,7 @@ impl Drop for AtomicBorrowRefMut {
     }
 }
 
-fn map(orig: AtomicRefMut) -> AtomicRefMut {
+fn map(orig: AtomicRefMut<'_>) -> AtomicRefMut<'_> {
     AtomicRefMut {
         value: orig.value,
         borrow: orig.borrow,
diff --git a/tests/ui/issues/issue-5708.rs b/tests/ui/issues/issue-5708.rs
@@ -25,7 +25,7 @@ struct Outer<'a> {
 }
 
 impl<'a> Outer<'a> {
-    fn new(inner: &dyn Inner) -> Outer {
+    fn new(inner: &dyn Inner) -> Outer<'_> {
         Outer {
             inner: inner
         }
diff --git a/tests/ui/late-bound-lifetimes/issue-47511.rs b/tests/ui/late-bound-lifetimes/issue-47511.rs
@@ -1,6 +1,6 @@
 //@ check-pass
 
-fn f(_: X) -> X {
+fn f(_: X<'_>) -> X<'_> {
     unimplemented!()
 }
 
diff --git a/tests/ui/late-bound-lifetimes/late_bound_through_alias.rs b/tests/ui/late-bound-lifetimes/late_bound_through_alias.rs
@@ -1,6 +1,6 @@
 //@ check-pass
 
-fn f(_: X) -> X {
+fn f(_: X<'_>) -> X<'_> {
     unimplemented!()
 }
 
diff --git a/tests/ui/lazy-type-alias/constrained-late-bound-regions.rs b/tests/ui/lazy-type-alias/constrained-late-bound-regions.rs
@@ -3,6 +3,7 @@
 
 #![feature(lazy_type_alias)]
 #![allow(incomplete_features)]
+#![allow(hidden_lifetimes_in_output_paths)]
 
 type Ref<'a> = &'a ();
 
diff --git a/tests/ui/lifetimes/elided-lifetime-in-path-in-impl-Fn.rs b/tests/ui/lifetimes/elided-lifetime-in-path-in-impl-Fn.rs
@@ -2,11 +2,11 @@
 
 struct Foo<'a>(&'a ());
 
-fn with_fn() -> fn(Foo) {
+fn with_fn() -> fn(Foo<'_>) {
     |_| ()
 }
 
-fn with_impl_fn() -> impl Fn(Foo) {
+fn with_impl_fn() -> impl Fn(Foo<'_>) {
     |_| ()
 }
 
diff --git a/tests/ui/lifetimes/issue-103582-hint-for-missing-lifetime-bound-on-trait-object-using-type-alias.fixed b/tests/ui/lifetimes/issue-103582-hint-for-missing-lifetime-bound-on-trait-object-using-type-alias.fixed
@@ -1,5 +1,7 @@
 //@ run-rustfix
 
+#![allow(hidden_lifetimes_in_output_paths)]
+
 trait Greeter0 {
     fn greet(&self);
 }
diff --git a/tests/ui/lifetimes/issue-103582-hint-for-missing-lifetime-bound-on-trait-object-using-type-alias.rs b/tests/ui/lifetimes/issue-103582-hint-for-missing-lifetime-bound-on-trait-object-using-type-alias.rs
@@ -1,5 +1,7 @@
 //@ run-rustfix
 
+#![allow(hidden_lifetimes_in_output_paths)]
+
 trait Greeter0 {
     fn greet(&self);
 }
diff --git a/tests/ui/lifetimes/issue-103582-hint-for-missing-lifetime-bound-on-trait-object-using-type-alias.stderr b/tests/ui/lifetimes/issue-103582-hint-for-missing-lifetime-bound-on-trait-object-using-type-alias.stderr
@@ -1,5 +1,5 @@
 error: lifetime may not live long enough
-  --> $DIR/issue-103582-hint-for-missing-lifetime-bound-on-trait-object-using-type-alias.rs:32:9
+  --> $DIR/issue-103582-hint-for-missing-lifetime-bound-on-trait-object-using-type-alias.rs:34:9
    |
 LL |     pub fn get(&self, i: usize) -> BoxedGreeter {
    |                - let's call the lifetime of this reference `'1`
diff --git a/tests/ui/lifetimes/mismatched-lifetime-syntaxes-details/missing-lifetime-kind.rs b/tests/ui/lifetimes/mismatched-lifetime-syntaxes-details/missing-lifetime-kind.rs
@@ -1,4 +1,5 @@
 #![deny(mismatched_lifetime_syntaxes)]
+#![allow(hidden_lifetimes_in_output_paths)]
 
 fn ampersand<'a>(x: &'a u8) -> &u8 {
     //~^ ERROR lifetime flowing from input to output with different syntax
diff --git a/tests/ui/lifetimes/mismatched-lifetime-syntaxes-details/missing-lifetime-kind.stderr b/tests/ui/lifetimes/mismatched-lifetime-syntaxes-details/missing-lifetime-kind.stderr
@@ -1,5 +1,5 @@
 error: lifetime flowing from input to output with different syntax
-  --> $DIR/missing-lifetime-kind.rs:3:22
+  --> $DIR/missing-lifetime-kind.rs:4:22
    |
 LL | fn ampersand<'a>(x: &'a u8) -> &u8 {
    |                      ^^        --- the elided lifetime gets resolved as `'a`
@@ -17,7 +17,7 @@ LL | fn ampersand<'a>(x: &'a u8) -> &'a u8 {
    |                                 ++
 
 error: lifetime flowing from input to output with different syntax
-  --> $DIR/missing-lifetime-kind.rs:10:21
+  --> $DIR/missing-lifetime-kind.rs:11:21
    |
 LL | fn brackets<'a>(x: &'a u8) -> Brackets {
    |                     ^^        -------- the elided lifetime gets resolved as `'a`
@@ -30,7 +30,7 @@ LL | fn brackets<'a>(x: &'a u8) -> Brackets<'a> {
    |                                       ++++
 
 error: lifetime flowing from input to output with different syntax
-  --> $DIR/missing-lifetime-kind.rs:17:18
+  --> $DIR/missing-lifetime-kind.rs:18:18
    |
 LL | fn comma<'a>(x: &'a u8) -> Comma<u8> {
    |                  ^^        --------- the elided lifetime gets resolved as `'a`
@@ -43,7 +43,7 @@ LL | fn comma<'a>(x: &'a u8) -> Comma<'a, u8> {
    |                                  +++
 
 error: lifetime flowing from input to output with different syntax
-  --> $DIR/missing-lifetime-kind.rs:22:23
+  --> $DIR/missing-lifetime-kind.rs:23:23
    |
 LL | fn underscore<'a>(x: &'a u8) -> &'_ u8 {
    |                       ^^         -- the elided lifetime gets resolved as `'a`
diff --git a/tests/ui/lifetimes/mismatched-lifetime-syntaxes-details/static.rs b/tests/ui/lifetimes/mismatched-lifetime-syntaxes-details/static.rs
@@ -1,4 +1,5 @@
 #![deny(mismatched_lifetime_syntaxes)]
+#![allow(hidden_lifetimes_in_output_paths)]
 
 use std::borrow::Cow;
 
diff --git a/tests/ui/lifetimes/mismatched-lifetime-syntaxes-details/static.stderr b/tests/ui/lifetimes/mismatched-lifetime-syntaxes-details/static.stderr
@@ -1,5 +1,5 @@
 error: lifetime flowing from input to output with different syntax
-  --> $DIR/static.rs:16:18
+  --> $DIR/static.rs:17:18
    |
 LL | fn ampersand(x: &'static u8) -> &u8 {
    |                  ^^^^^^^        --- the elided lifetime gets resolved as `'static`
@@ -17,7 +17,7 @@ LL | fn ampersand(x: &'static u8) -> &'static u8 {
    |                                  +++++++
 
 error: lifetime flowing from input to output with different syntax
-  --> $DIR/static.rs:23:17
+  --> $DIR/static.rs:24:17
    |
 LL | fn brackets(x: &'static u8) -> Brackets {
    |                 ^^^^^^^        -------- the elided lifetime gets resolved as `'static`
@@ -30,7 +30,7 @@ LL | fn brackets(x: &'static u8) -> Brackets<'static> {
    |                                        +++++++++
 
 error: lifetime flowing from input to output with different syntax
-  --> $DIR/static.rs:30:14
+  --> $DIR/static.rs:31:14
    |
 LL | fn comma(x: &'static u8) -> Comma<u8> {
    |              ^^^^^^^        --------- the elided lifetime gets resolved as `'static`
@@ -43,7 +43,7 @@ LL | fn comma(x: &'static u8) -> Comma<'static, u8> {
    |                                   ++++++++
 
 error: lifetime flowing from input to output with different syntax
-  --> $DIR/static.rs:35:19
+  --> $DIR/static.rs:36:19
    |
 LL | fn underscore(x: &'static u8) -> &'_ u8 {
    |                   ^^^^^^^         -- the elided lifetime gets resolved as `'static`
diff --git a/tests/ui/lifetimes/mismatched-lifetime-syntaxes.rs b/tests/ui/lifetimes/mismatched-lifetime-syntaxes.rs
diff --git a/tests/ui/macros/format-args-temporaries.rs b/tests/ui/macros/format-args-temporaries.rs
diff --git a/tests/ui/mir/mir_coercions.rs b/tests/ui/mir/mir_coercions.rs
diff --git a/tests/ui/mir/mir_fat_ptr.rs b/tests/ui/mir/mir_fat_ptr.rs
diff --git a/tests/ui/nll/issue-53570.rs b/tests/ui/nll/issue-53570.rs
diff --git a/tests/ui/nll/issue-54556-niconii.rs b/tests/ui/nll/issue-54556-niconii.rs
diff --git a/tests/ui/regions/init-res-into-things.rs b/tests/ui/regions/init-res-into-things.rs
diff --git a/tests/ui/regions/regions-nullary-variant.rs b/tests/ui/regions/regions-nullary-variant.rs
diff --git a/tests/ui/resource-assign-is-not-copy.rs b/tests/ui/resource-assign-is-not-copy.rs
diff --git a/tests/ui/resource-destruct.rs b/tests/ui/resource-destruct.rs
diff --git a/tests/ui/rfcs/rfc-2497-if-let-chains/temporary-early-drop.rs b/tests/ui/rfcs/rfc-2497-if-let-chains/temporary-early-drop.rs
diff --git a/tests/ui/structs-enums/resource-in-struct.rs b/tests/ui/structs-enums/resource-in-struct.rs
diff --git a/tests/ui/type-id-higher-rank-2.rs b/tests/ui/type-id-higher-rank-2.rs
diff --git a/tests/ui/underscore-lifetimes.rs b/tests/ui/underscore-lifetimes.rs

Original file line number	Diff line number	Diff line change
`@@ -136,7 +136,7 @@ declare_lint! {`
`136`	`136`	`///`
`137`	`137`	`/// [placeholder lifetime]: https://doc.rust-lang.org/reference/lifetime-elision.html#lifetime-elision-in-functions`
`138`	`138`	`pub HIDDEN_LIFETIMES_IN_OUTPUT_PATHS,`
`139`		`- Allow,`
	`139`	`+ Warn,`
`140`	`140`	`"hidden lifetime parameters in types in function return values are deprecated"`
`141`	`141`	`}`
`142`	`142`
Original file line number	Diff line number	Diff line change
`@@ -21,7 +21,7 @@ trait Iterator {`
`21`	`21`	`}`
`22`	`22`
`23`	`23`	`trait IteratorExt: Iterator + Sized {`
`24`		`- fn by_ref(&mut self) -> ByRef<Self> {`
	`24`	`+ fn by_ref(&mut self) -> ByRef<'_, Self> {`
`25`	`25`	`ByRef(self)`
`26`	`26`	`}`
`27`	`27`	`}`
Original file line number	Diff line number	Diff line change
`@@ -21,11 +21,11 @@ trait SliceExt2 {`
`21`	`21`	`impl<T> SliceExt2 for [T] {`
`22`	`22`	`type Item = T;`
`23`	`23`
`24`		`- fn split2<P>(&self, pred: P) -> Splits<T, P> where P: FnMut(&T) -> bool {`
	`24`	`+ fn split2<P>(&self, pred: P) -> Splits<'_, T, P> where P: FnMut(&T) -> bool {`
`25`	`25`	`loop {}`
`26`	`26`	`}`
`27`	`27`
`28`		`- fn splitn2<P>(&self, n: u32, pred: P) -> SplitsN<Splits<T, P>> where P: FnMut(&T) -> bool {`
	`28`	`+ fn splitn2<P>(&self, n: u32, pred: P) -> SplitsN<Splits<'_, T, P>> where P: FnMut(&T) -> bool {`
`29`	`29`	`SliceExt2::split2(self, pred);`
`30`	`30`	`loop {}`
`31`	`31`	`}`
Original file line number	Diff line number	Diff line change
`@@ -20,7 +20,7 @@ trait Iterator {`
`20`	`20`	`}`
`21`	`21`
`22`	`22`	`trait IteratorExt: Iterator + Sized {`
`23`		`- fn by_ref(&mut self) -> ByRef<Self> {`
	`23`	`+ fn by_ref(&mut self) -> ByRef<'_, Self> {`
`24`	`24`	`ByRef(self)`
`25`	`25`	`}`
`26`	`26`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1,3 +1,5 @@`
	`1`	`+#![allow(hidden_lifetimes_in_output_paths)]`
	`2`	`+`
`1`	`3`	`// Check that you are allowed to implement using elision but write`
`2`	`4`	`// trait without elision (a bug in this cropped up during`
`3`	`5`	`// bootstrapping, so this is a regression test).`
Original file line number	Diff line number	Diff line change
`@@ -50,7 +50,7 @@ where P: Pixel + 'static,`
`50`	`50`	`loop { }`
`51`	`51`	`}`
`52`	`52`
`53`		`- pub fn pixels_mut(&mut self) -> PixelsMut<P> {`
	`53`	`+ pub fn pixels_mut(&mut self) -> PixelsMut<'_, P> {`
`54`	`54`	`loop { }`
`55`	`55`	`}`
`56`	`56`	`}`
Original file line number	Diff line number	Diff line change
`@@ -7,7 +7,7 @@ pub struct HelperStruct<'n> {`
`7`	`7`	`}`
`8`	`8`
`9`	`9`	`impl DataStruct {`
`10`		`- pub fn f(&self) -> HelperStruct {`
	`10`	`+ pub fn f(&self) -> HelperStruct<'_> {`
`11`	`11`	`let helpers = [vec![], vec![]];`
`12`	`12`
`13`	`13`	`HelperStruct { helpers: helpers.clone(), is_empty: helpers[0].is_empty() }`
Original file line number	Diff line number	Diff line change
`@@ -17,7 +17,7 @@ LL + #![feature(unsized_const_params)]`
`17`	`17`	error: `&'static str` is forbidden as the type of a const generic parameter
`18`	`18`	`--> $DIR/issue-71348.rs:18:25`
`19`	`19`	`\|`
`20`		`-LL \| fn ask<'a, const N: &'static str>(&'a self) -> &'a <Self as Get<N>>::Target`
	`20`	`+LL \| fn ask<'a, const N: &'static str>(&'a self) -> &'a <Self as Get<'a, N>>::Target`
`21`	`21`	`\| ^^^^^^^^^^^^`
`22`	`22`	`\|`
`23`	`23`	= note: the only supported types are integers, `bool`, and `char`
Original file line number	Diff line number	Diff line change
`@@ -15,9 +15,8 @@ trait Get<'a, const N: &'static str> {`
`15`	`15`	`}`
`16`	`16`
`17`	`17`	`impl Foo {`
`18`		`- fn ask<'a, const N: &'static str>(&'a self) -> &'a <Self as Get<N>>::Target`
	`18`	`+ fn ask<'a, const N: &'static str>(&'a self) -> &'a <Self as Get<'a, N>>::Target`
`19`	`19`	//[min]~^ ERROR `&'static str` is forbidden as the type of a const generic parameter
`20`		`- //[full]~^^ WARNING lifetime flowing from input to output with different syntax`
`21`	`20`	`where`
`22`	`21`	`Self: Get<'a, N>,`
`23`	`22`	`{`
Original file line number	Diff line number	Diff line change
`@@ -548,7 +548,7 @@ impl Events {`
`548`	`548`	`Ok(LogDrop(self, m))`
`549`	`549`	`}`
`550`	`550`	/// Return an `Err` value that logs its drop.
`551`		`- fn err(&self, m: u64) -> Result<LogDrop, LogDrop> {`
	`551`	`+ fn err(&self, m: u64) -> Result<LogDrop<'_>, LogDrop<'_>> {`
`552`	`552`	`Err(LogDrop(self, m))`
`553`	`553`	`}`
`554`	`554`	`/// Log an event.`