1 files changed, 23 insertions, 0 deletions
diff --git a/tests/ui/lint/issue-109152.stderr b/tests/ui/lint/issue-109152.stderr
new file mode 100644
index 000000000..7db9e71a5
--- /dev/null
+++ b/tests/ui/lint/issue-109152.stderr
@@ -0,0 +1,23 @@
+error: `Iterator::map` call that discard the iterator's values
+  --> $DIR/issue-109152.rs:5:21
+   |
+LL |     vec![42].iter().map(drop);
+   |                     ^^^^----^
+   |                     |   |
+   |                     |   this function returns `()`, which is likely not what you wanted
+   |                     |   called `Iterator::map` with callable that returns `()`
+   |                     after this call to map, the resulting iterator is `impl Iterator<Item = ()>`, which means the only information carried by the iterator is the number of items
+   |
+   = note: `Iterator::map`, like many of the methods on `Iterator`, gets executed lazily, meaning that its effects won't be visible until it is iterated
+note: the lint level is defined here
+  --> $DIR/issue-109152.rs:1:9
+   |
+LL | #![deny(map_unit_fn)]
+   |         ^^^^^^^^^^^
+help: you might have meant to use `Iterator::for_each`
+   |
+LL |     vec![42].iter().for_each(drop);
+   |                     ~~~~~~~~
+
+error: aborting due to previous error
+