New upstream version 1.46.0~beta.2+dfsg1

[rustc.git] / src / libcore / iter / traits / iterator.rs

diff --git a/src/libcore/iter/traits/iterator.rs b/src/libcore/iter/traits/iterator.rs
index a10b34d931d10a9080d90db05fcb6ab67a03204d..ce4be973140e58fa8a182daad5acbc350e339f38 100644 (file)
--- a/src/libcore/iter/traits/iterator.rs
+++ b/src/libcore/iter/traits/iterator.rs
@@ -1521,7 +1521,7 @@ pub trait Iterator {
     ///
     /// let iter = a.iter();
     ///
-    /// let sum: i32 = iter.take(5).fold(0, |acc, i| acc + i );
+    /// let sum: i32 = iter.take(5).fold(0, |acc, i| acc + i);
     ///
     /// assert_eq!(sum, 6);
     ///
@@ -1535,7 +1535,7 @@ pub trait Iterator {
     /// let mut iter = a.iter();
     ///
     /// // instead, we add in a .by_ref()
-    /// let sum: i32 = iter.by_ref().take(2).fold(0, |acc, i| acc + i );
+    /// let sum: i32 = iter.by_ref().take(2).fold(0, |acc, i| acc + i);
     ///
     /// assert_eq!(sum, 3);
     ///
@@ -2265,7 +2265,7 @@ pub trait Iterator {
     }
 
     /// Applies function to the elements of iterator and returns
-    /// the first non-none result or the first error.
+    /// the first true result or the first error.
     ///
     /// # Examples
     ///
@@ -2286,19 +2286,26 @@ pub trait Iterator {
     /// ```
     #[inline]
     #[unstable(feature = "try_find", reason = "new API", issue = "63178")]
-    fn try_find<F, E, R>(&mut self, mut f: F) -> Result<Option<Self::Item>, E>
+    fn try_find<F, R>(&mut self, f: F) -> Result<Option<Self::Item>, R::Error>
     where
         Self: Sized,
         F: FnMut(&Self::Item) -> R,
-        R: Try<Ok = bool, Error = E>,
+        R: Try<Ok = bool>,
     {
-        self.try_fold((), move |(), x| match f(&x).into_result() {
-            Ok(false) => LoopState::Continue(()),
-            Ok(true) => LoopState::Break(Ok(x)),
-            Err(x) => LoopState::Break(Err(x)),
-        })
-        .break_value()
-        .transpose()
+        #[inline]
+        fn check<F, T, R>(mut f: F) -> impl FnMut((), T) -> LoopState<(), Result<T, R::Error>>
+        where
+            F: FnMut(&T) -> R,
+            R: Try<Ok = bool>,
+        {
+            move |(), x| match f(&x).into_result() {
+                Ok(false) => LoopState::Continue(()),
+                Ok(true) => LoopState::Break(Ok(x)),
+                Err(x) => LoopState::Break(Err(x)),
+            }
+        }
+
+        self.try_fold((), check(f)).break_value().transpose()
     }
 
     /// Searches for an element in an iterator, returning its index.
@@ -2717,12 +2724,12 @@ pub trait Iterator {
     /// ```
     /// let a = [1, 2, 3];
     ///
-    /// let v_cloned: Vec<_> = a.iter().copied().collect();
+    /// let v_copied: Vec<_> = a.iter().copied().collect();
     ///
     /// // copied is the same as .map(|&x| x)
     /// let v_map: Vec<_> = a.iter().map(|&x| x).collect();
     ///
-    /// assert_eq!(v_cloned, vec![1, 2, 3]);
+    /// assert_eq!(v_copied, vec![1, 2, 3]);
     /// assert_eq!(v_map, vec![1, 2, 3]);
     /// ```
     #[stable(feature = "iter_copied", since = "1.36.0")]