Auto merge of rust-lang#10254 - tylerjw:issue_6929, r=Manishearth

bors · bors · commit d92070a7b9bf · 2023-01-30T17:30:32.000Z
needless_range_loop: improve documentation fixes rust-lang#6929 changelog: [`needless_range_loop`]: improve documentation
diff --git a/clippy_lints/src/loops/mod.rs b/clippy_lints/src/loops/mod.rs
@@ -61,7 +61,8 @@ declare_clippy_lint! {
     ///
     /// ### Why is this bad?
     /// Just iterating the collection itself makes the intent
-    /// more clear and is probably faster.
+    /// more clear and is probably faster because it eliminates
+    /// the bounds check that is done when indexing.
     ///
     /// ### Example
     /// ```rust
diff --git a/clippy_lints/src/loops/needless_range_loop.rs b/clippy_lints/src/loops/needless_range_loop.rs
@@ -149,7 +149,7 @@ pub(super) fn check<'tcx>(
                         |diag| {
                             multispan_sugg(
                                 diag,
-                                "consider using an iterator",
+                                "consider using an iterator and enumerate()",
                                 vec![
                                     (pat.span, format!("({}, <item>)", ident.name)),
                                     (
diff --git a/tests/ui/needless_range_loop.stderr b/tests/ui/needless_range_loop.stderr
@@ -49,7 +49,7 @@ error: the loop variable `i` is used to index `vec`
 LL |     for i in 0..vec.len() {
    |              ^^^^^^^^^^^^
    |
-help: consider using an iterator
+help: consider using an iterator and enumerate()
    |
 LL |     for (i, <item>) in vec.iter().enumerate() {
    |         ~~~~~~~~~~~    ~~~~~~~~~~~~~~~~~~~~~~
@@ -126,7 +126,7 @@ error: the loop variable `i` is used to index `vec`
 LL |     for i in 5..vec.len() {
    |              ^^^^^^^^^^^^
    |
-help: consider using an iterator
+help: consider using an iterator and enumerate()
    |
 LL |     for (i, <item>) in vec.iter().enumerate().skip(5) {
    |         ~~~~~~~~~~~    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -137,7 +137,7 @@ error: the loop variable `i` is used to index `vec`
 LL |     for i in 5..10 {
    |              ^^^^^
    |
-help: consider using an iterator
+help: consider using an iterator and enumerate()
    |
 LL |     for (i, <item>) in vec.iter().enumerate().take(10).skip(5) {
    |         ~~~~~~~~~~~    ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -148,7 +148,7 @@ error: the loop variable `i` is used to index `vec`
 LL |     for i in 0..vec.len() {
    |              ^^^^^^^^^^^^
    |
-help: consider using an iterator
+help: consider using an iterator and enumerate()
    |
 LL |     for (i, <item>) in vec.iter_mut().enumerate() {
    |         ~~~~~~~~~~~    ~~~~~~~~~~~~~~~~~~~~~~~~~~

Original file line number	Diff line number	Diff line change
`@@ -149,7 +149,7 @@ pub(super) fn check<'tcx>(`
`149`	`149`	`\|diag\| {`
`150`	`150`	`multispan_sugg(`
`151`	`151`	`diag,`
`152`		`- "consider using an iterator",`
	`152`	`+ "consider using an iterator and enumerate()",`
`153`	`153`	`vec![`
`154`	`154`	`(pat.span, format!("({}, <item>)", ident.name)),`
`155`	`155`	`(`
Original file line number	Diff line number	Diff line change
@@ -49,7 +49,7 @@ error: the loop variable `i` is used to index `vec`
`49`	`49`	`LL \| for i in 0..vec.len() {`
`50`	`50`	`\| ^^^^^^^^^^^^`
`51`	`51`	`\|`
`52`		`-help: consider using an iterator`
	`52`	`+help: consider using an iterator and enumerate()`
`53`	`53`	`\|`
`54`	`54`	`LL \| for (i, <item>) in vec.iter().enumerate() {`
`55`	`55`	`\| ~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~`
@@ -126,7 +126,7 @@ error: the loop variable `i` is used to index `vec`
`126`	`126`	`LL \| for i in 5..vec.len() {`
`127`	`127`	`\| ^^^^^^^^^^^^`
`128`	`128`	`\|`
`129`		`-help: consider using an iterator`
	`129`	`+help: consider using an iterator and enumerate()`
`130`	`130`	`\|`
`131`	`131`	`LL \| for (i, <item>) in vec.iter().enumerate().skip(5) {`
`132`	`132`	`\| ~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~`
@@ -137,7 +137,7 @@ error: the loop variable `i` is used to index `vec`
`137`	`137`	`LL \| for i in 5..10 {`
`138`	`138`	`\| ^^^^^`
`139`	`139`	`\|`
`140`		`-help: consider using an iterator`
	`140`	`+help: consider using an iterator and enumerate()`
`141`	`141`	`\|`
`142`	`142`	`LL \| for (i, <item>) in vec.iter().enumerate().take(10).skip(5) {`
`143`	`143`	`\| ~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~`
@@ -148,7 +148,7 @@ error: the loop variable `i` is used to index `vec`
`148`	`148`	`LL \| for i in 0..vec.len() {`
`149`	`149`	`\| ^^^^^^^^^^^^`
`150`	`150`	`\|`
`151`		`-help: consider using an iterator`
	`151`	`+help: consider using an iterator and enumerate()`
`152`	`152`	`\|`
`153`	`153`	`LL \| for (i, <item>) in vec.iter_mut().enumerate() {`
`154`	`154`	`\| ~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~`