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Diffstat (limited to 'tests/ui/lint/lint_map_unit_fn.stderr')
| -rw-r--r-- | tests/ui/lint/lint_map_unit_fn.stderr | 66 |
1 files changed, 66 insertions, 0 deletions
diff --git a/tests/ui/lint/lint_map_unit_fn.stderr b/tests/ui/lint/lint_map_unit_fn.stderr new file mode 100644 index 000000000..fbf689c54 --- /dev/null +++ b/tests/ui/lint/lint_map_unit_fn.stderr @@ -0,0 +1,66 @@ +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` + | +LL | x.iter_mut().for_each(foo); + | ~~~~~~~~ + +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` + | +LL | x.iter_mut().for_each(f); + | ~~~~~~~~ + +error: aborting due to 3 previous errors + |