1 files changed, 40 insertions, 0 deletions

diff --git a/src/test/ui/issues/issue-31173.stderr b/src/test/ui/issues/issue-31173.stderr
new file mode 100644
index 000000000..68337a715
--- /dev/null
+++ b/src/test/ui/issues/issue-31173.stderr
@@ -0,0 +1,40 @@
+error[E0271]: type mismatch resolving `<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 6:43]> as Iterator>::Item == &_`
+  --> $DIR/issue-31173.rs:10:10
+   |
+LL |         .cloned()
+   |          ^^^^^^ expected reference, found `u8`
+   |
+   = note: expected reference `&_`
+                   found type `u8`
+note: required by a bound in `cloned`
+  --> $SRC_DIR/core/src/iter/traits/iterator.rs:LL:COL
+   |
+LL |         Self: Sized + Iterator<Item = &'a T>,
+   |                                ^^^^^^^^^^^^ required by this bound in `cloned`
+
+error[E0599]: the method `collect` exists for struct `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 6:43]>>`, but its trait bounds were not satisfied
+  --> $DIR/issue-31173.rs:12:10
+   |
+LL |         .collect();
+   |          ^^^^^^^ method cannot be called on `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 6:43]>>` due to unsatisfied trait bounds
+   |
+  ::: $SRC_DIR/core/src/iter/adapters/cloned.rs:LL:COL
+   |
+LL | pub struct Cloned<I> {
+   | -------------------- doesn't satisfy `_: Iterator`
+   |
+  ::: $SRC_DIR/core/src/iter/adapters/take_while.rs:LL:COL
+   |
+LL | pub struct TakeWhile<I, P> {
+   | -------------------------- doesn't satisfy `<_ as Iterator>::Item = &_`
+   |
+   = note: the following trait bounds were not satisfied:
+           `<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 6:43]> as Iterator>::Item = &_`
+           which is required by `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 6:43]>>: Iterator`
+           `Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 6:43]>>: Iterator`
+           which is required by `&mut Cloned<TakeWhile<&mut std::vec::IntoIter<u8>, [closure@$DIR/issue-31173.rs:6:39: 6:43]>>: Iterator`
+
+error: aborting due to 2 previous errors
+
+Some errors have detailed explanations: E0271, E0599.
+For more information about an error, try `rustc --explain E0271`.