error: `Iterator::map` call that discard the iterator's values
--> $DIR/lint_map_unit_fn.rs:9:18
|
LL | fn foo(items: &mut Vec<u8>) {
| --------------------------- this function returns `()`, which is likely not what you wanted
...
LL | x.iter_mut().map(foo);
| ^^^^---^
| | |
| | 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/lint_map_unit_fn.rs:1:9
|
LL | #![deny(map_unit_fn)]
| ^^^^^^^^^^^
help: you might have meant to use `Iterator::for_each`
error: `Iterator::map` call that discard the iterator's values
--> $DIR/lint_map_unit_fn.rs:11:18
|
LL | x.iter_mut().map(|items| {
| ^ -------
| | |
| ____________________|___this function returns `()`, which is likely not what you wanted
| | __________________|
| | |
LL | | |
LL | | | items.sort();
LL | | | });
| | | -^ 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
| | |_____||
| |_______|
| called `Iterator::map` with callable that returns `()`
|
= 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
help: you might have meant to use `Iterator::for_each`
|
LL | x.iter_mut().for_each(|items| {
| ~~~~~~~~
error: `Iterator::map` call that discard the iterator's values
--> $DIR/lint_map_unit_fn.rs:18:18
|
LL | let f = |items: &mut Vec<u8>| {
| --------------------- this function returns `()`, which is likely not what you wanted
...
LL | x.iter_mut().map(f);
| ^^^^-^
| | |
| | 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
help: you might have meant to use `Iterator::for_each`
