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`
