std: Require `&mut self` for Iterator::all

Keeps the method consistent with `Iterator::any`.

Closes #22617
[breaking-change]

1 files changed, 2 insertions, 2 deletions

diff --git a/src/libcore/iter.rs b/src/libcore/iter.rs
index 48ec1342971..f82538e0b2a 100644
--- a/src/libcore/iter.rs
+++ b/src/libcore/iter.rs
@@ -637,8 +637,8 @@ pub trait IteratorExt: Iterator + Sized {
     /// ```
     #[inline]
     #[stable(feature = "rust1", since = "1.0.0")]
-    fn all<F>(self, mut f: F) -> bool where F: FnMut(Self::Item) -> bool {
-        for x in self { if !f(x) { return false; } }
+    fn all<F>(&mut self, mut f: F) -> bool where F: FnMut(Self::Item) -> bool {
+        for x in self.by_ref() { if !f(x) { return false; } }
         true
     }