Adjust docs and tests for new IntoIterator impl for arrays

Author: LukasKalbertodt

src/libstd/primitive_docs.rs

@@ -464,7 +464,7 @@ mod prim_pointer { }
 /// the element type allows it:
 ///
 /// - [`Debug`][debug]
-/// - [`IntoIterator`][intoiterator] (implemented for `&[T; N]` and `&mut [T; N]`)
+/// - [`IntoIterator`][intoiterator] (implemented for `[T; N]`, `&[T; N]` and `&mut [T; N]`)
 /// - [`PartialEq`][partialeq], [`PartialOrd`][partialord], [`Eq`][eq], [`Ord`][ord]
 /// - [`Hash`][hash]
 /// - [`AsRef`][asref], [`AsMut`][asmut]
@@ -500,32 +500,16 @@ mod prim_pointer { }
 /// assert_eq!([1, 2], &array[1..]);
 ///
 /// // This loop prints: 0 1 2
-/// for x in &array {
+/// for x in array {
 ///     print!("{} ", x);
 /// }
 /// ```
 ///
-/// An array itself is not iterable:
-///
-/// ```compile_fail,E0277
-/// let array: [i32; 3] = [0; 3];
-///
-/// for x in array { }
-/// // error: the trait bound `[i32; 3]: std::iter::Iterator` is not satisfied
-/// ```
-///
-/// The solution is to coerce the array to a slice by calling a slice method:
+/// You can also iterate over reference to the array's elements:
 ///
 /// ```
-/// # let array: [i32; 3] = [0; 3];
-/// for x in array.iter() { }
-/// ```
-///
-/// If the array has 32 or fewer elements (see above), you can also use the
-/// array reference's [`IntoIterator`] implementation:
+/// let array: [i32; 3] = [0; 3];
 ///
-/// ```
-/// # let array: [i32; 3] = [0; 3];
 /// for x in &array { }
 /// ```
 ///

src/test/ui/const-generics/array-impls/core-traits-no-impls-length-33.stderr

@@ -46,6 +46,7 @@ LL |     for _ in &[0_usize; 33] {
              <&'a [T] as std::iter::IntoIterator>
              <&'a mut [T; _] as std::iter::IntoIterator>
              <&'a mut [T] as std::iter::IntoIterator>
+             <[T; _] as std::iter::IntoIterator>
    = note: required by `std::iter::IntoIterator::into_iter`
 
 error: aborting due to 5 previous errors

src/test/ui/iterators/array-of-ranges.rs

@@ -1,23 +1,16 @@
+// check-pass
+
 fn main() {
     for _ in [0..1] {}
-//~^ ERROR is not an iterator
     for _ in [0..=1] {}
-//~^ ERROR is not an iterator
     for _ in [0..] {}
-//~^ ERROR is not an iterator
     for _ in [..1] {}
-//~^ ERROR is not an iterator
     for _ in [..=1] {}
-//~^ ERROR is not an iterator
     let start = 0;
     let end = 0;
     for _ in [start..end] {}
-//~^ ERROR is not an iterator
     let array_of_range = [start..end];
     for _ in array_of_range {}
-//~^ ERROR is not an iterator
     for _ in [0..1, 2..3] {}
-//~^ ERROR is not an iterator
     for _ in [0..=1] {}
-//~^ ERROR is not an iterator
 }

src/test/ui/iterators/array-of-ranges.stderr

@@ -1,9 +1,8 @@
+// check-pass
+
 fn main() {
     for _ in [1, 2] {}
-//~^ ERROR is not an iterator
     let x = [1, 2];
     for _ in x {}
-//~^ ERROR is not an iterator
     for _ in [1.0, 2.0] {}
-//~^ ERROR is not an iterator
 }

src/test/ui/iterators/array.rs

@@ -6,12 +6,6 @@ fn main() {
     let big = [0u8; 33];
 
     // Expressions that should trigger the lint
-    small.iter();
-    //~^ WARNING this method call currently resolves to `<&[T; N] as IntoIterator>::into_iter`
-    //~| WARNING this was previously accepted by the compiler but is being phased out
-    [1, 2].iter();
-    //~^ WARNING this method call currently resolves to `<&[T; N] as IntoIterator>::into_iter`
-    //~| WARNING this was previously accepted by the compiler but is being phased out
     big.iter();
     //~^ WARNING this method call currently resolves to `<&[T] as IntoIterator>::into_iter`
     //~| WARNING this was previously accepted by the compiler but is being phased out
@@ -21,6 +15,8 @@ fn main() {
 
 
     // Expressions that should not
+    small.into_iter();
+    [1, 2].into_iter();
     (&[1, 2]).into_iter();
     (&small).into_iter();
     (&[0u8; 33]).into_iter();

src/test/ui/iterators/array.stderr

@@ -6,12 +6,6 @@ fn main() {
     let big = [0u8; 33];
 
     // Expressions that should trigger the lint
-    small.into_iter();
-    //~^ WARNING this method call currently resolves to `<&[T; N] as IntoIterator>::into_iter`
-    //~| WARNING this was previously accepted by the compiler but is being phased out
-    [1, 2].into_iter();
-    //~^ WARNING this method call currently resolves to `<&[T; N] as IntoIterator>::into_iter`
-    //~| WARNING this was previously accepted by the compiler but is being phased out
     big.into_iter();
     //~^ WARNING this method call currently resolves to `<&[T] as IntoIterator>::into_iter`
     //~| WARNING this was previously accepted by the compiler but is being phased out
@@ -21,6 +15,8 @@ fn main() {
 
 
     // Expressions that should not
+    small.into_iter();
+    [1, 2].into_iter();
     (&[1, 2]).into_iter();
     (&small).into_iter();
     (&[0u8; 33]).into_iter();

src/test/ui/iterators/into-iter-on-arrays-lint.fixed

@@ -1,33 +1,15 @@
-warning: this method call currently resolves to `<&[T; N] as IntoIterator>::into_iter` (due to autoref coercions), but that might change in the future when `IntoIterator` impls for arrays are added.
-  --> $DIR/into-iter-on-arrays-lint.rs:9:11
-   |
-LL |     small.into_iter();
-   |           ^^^^^^^^^ help: use `.iter()` instead of `.into_iter()` to avoid ambiguity: `iter`
-   |
-   = note: `#[warn(array_into_iter)]` on by default
-   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
-   = note: for more information, see issue #66145 <https://github.com/rust-lang/rust/issues/66145>
-
-warning: this method call currently resolves to `<&[T; N] as IntoIterator>::into_iter` (due to autoref coercions), but that might change in the future when `IntoIterator` impls for arrays are added.
-  --> $DIR/into-iter-on-arrays-lint.rs:12:12
-   |
-LL |     [1, 2].into_iter();
-   |            ^^^^^^^^^ help: use `.iter()` instead of `.into_iter()` to avoid ambiguity: `iter`
-   |
-   = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
-   = note: for more information, see issue #66145 <https://github.com/rust-lang/rust/issues/66145>
-
 warning: this method call currently resolves to `<&[T] as IntoIterator>::into_iter` (due to autoref coercions), but that might change in the future when `IntoIterator` impls for arrays are added.
-  --> $DIR/into-iter-on-arrays-lint.rs:15:9
+  --> $DIR/into-iter-on-arrays-lint.rs:9:9
    |
 LL |     big.into_iter();
    |         ^^^^^^^^^ help: use `.iter()` instead of `.into_iter()` to avoid ambiguity: `iter`
    |
+   = note: `#[warn(array_into_iter)]` on by default
    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
    = note: for more information, see issue #66145 <https://github.com/rust-lang/rust/issues/66145>
 
 warning: this method call currently resolves to `<&[T] as IntoIterator>::into_iter` (due to autoref coercions), but that might change in the future when `IntoIterator` impls for arrays are added.
-  --> $DIR/into-iter-on-arrays-lint.rs:18:15
+  --> $DIR/into-iter-on-arrays-lint.rs:12:15
    |
 LL |     [0u8; 33].into_iter();
    |               ^^^^^^^^^ help: use `.iter()` instead of `.into_iter()` to avoid ambiguity: `iter`