3 files changed, 12 insertions, 13 deletions
diff --git a/src/libcore/iter/adapters/flatten.rs b/src/libcore/iter/adapters/flatten.rs
index 8eb81fbb2c6..8c2aae477bf 100644
--- a/src/libcore/iter/adapters/flatten.rs
+++ b/src/libcore/iter/adapters/flatten.rs
@@ -34,7 +34,7 @@ impl<I: Clone, U: Clone + IntoIterator, F: Clone> Clone for FlatMap<I, U, F>
 impl<I: fmt::Debug, U: IntoIterator, F> fmt::Debug for FlatMap<I, U, F>
     where U::IntoIter: fmt::Debug
 {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("FlatMap").field("inner", &self.inner).finish()
     }
 }
@@ -120,7 +120,7 @@ impl<I, U> fmt::Debug for Flatten<I>
     where I: Iterator + fmt::Debug, U: Iterator + fmt::Debug,
           I::Item: IntoIterator<IntoIter = U, Item = U::Item>,
 {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Flatten").field("inner", &self.inner).finish()
     }
 }
@@ -328,4 +328,3 @@ impl<I, U> DoubleEndedIterator for FlattenCompat<I, U>
             .rfold(init, |acc, iter| iter.rfold(acc, &mut fold))
     }
 }
-
diff --git a/src/libcore/iter/adapters/mod.rs b/src/libcore/iter/adapters/mod.rs
index ce18b4b97ad..61e6ab6b48a 100644
--- a/src/libcore/iter/adapters/mod.rs
+++ b/src/libcore/iter/adapters/mod.rs
@@ -553,7 +553,7 @@ impl<I, F> Map<I, F> {
 
 #[stable(feature = "core_impl_debug", since = "1.9.0")]
 impl<I: fmt::Debug, F> fmt::Debug for Map<I, F> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Map")
             .field("iter", &self.iter)
             .finish()
@@ -669,7 +669,7 @@ impl<I, P> Filter<I, P> {
 
 #[stable(feature = "core_impl_debug", since = "1.9.0")]
 impl<I: fmt::Debug, P> fmt::Debug for Filter<I, P> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Filter")
             .field("iter", &self.iter)
             .finish()
@@ -793,7 +793,7 @@ impl<I, F> FilterMap<I, F> {
 
 #[stable(feature = "core_impl_debug", since = "1.9.0")]
 impl<I: fmt::Debug, F> fmt::Debug for FilterMap<I, F> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("FilterMap")
             .field("iter", &self.iter)
             .finish()
@@ -1222,7 +1222,7 @@ impl<I, P> SkipWhile<I, P> {
 
 #[stable(feature = "core_impl_debug", since = "1.9.0")]
 impl<I: fmt::Debug, P> fmt::Debug for SkipWhile<I, P> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("SkipWhile")
             .field("iter", &self.iter)
             .field("flag", &self.flag)
@@ -1310,7 +1310,7 @@ impl<I, P> TakeWhile<I, P> {
 
 #[stable(feature = "core_impl_debug", since = "1.9.0")]
 impl<I: fmt::Debug, P> fmt::Debug for TakeWhile<I, P> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("TakeWhile")
             .field("iter", &self.iter)
             .field("flag", &self.flag)
@@ -1634,7 +1634,7 @@ impl<I, St, F> Scan<I, St, F> {
 
 #[stable(feature = "core_impl_debug", since = "1.9.0")]
 impl<I: fmt::Debug, St: fmt::Debug, F> fmt::Debug for Scan<I, St, F> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Scan")
             .field("iter", &self.iter)
             .field("state", &self.state)
@@ -1928,7 +1928,7 @@ impl<I, F> Inspect<I, F> {
 
 #[stable(feature = "core_impl_debug", since = "1.9.0")]
 impl<I: fmt::Debug, F> fmt::Debug for Inspect<I, F> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Inspect")
             .field("iter", &self.iter)
             .finish()
diff --git a/src/libcore/iter/sources.rs b/src/libcore/iter/sources.rs
index c4f6fbf0ff2..70a3b70c180 100644
--- a/src/libcore/iter/sources.rs
+++ b/src/libcore/iter/sources.rs
@@ -200,7 +200,7 @@ pub struct Empty<T>(marker::PhantomData<T>);
 
 #[stable(feature = "core_impl_debug", since = "1.9.0")]
 impl<T> fmt::Debug for Empty<T> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.pad("Empty")
     }
 }
@@ -558,7 +558,7 @@ impl<T, F> Iterator for FromFn<F>
 
 #[stable(feature = "iter_from_fn", since = "1.34.0")]
 impl<F> fmt::Debug for FromFn<F> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("FromFn").finish()
     }
 }
@@ -631,7 +631,7 @@ impl<T, F> FusedIterator for Successors<T, F>
 
 #[stable(feature = "iter_successors", since = "1.34.0")]
 impl<T: fmt::Debug, F> fmt::Debug for Successors<T, F> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Successors")
             .field("next", &self.next)
             .finish()