Auto-generate lint documentation.

compiler/rustc_lint/src/array_into_iter.rs

@@ -7,6 +7,31 @@ use rustc_session::lint::FutureIncompatibleInfo;
 use rustc_span::symbol::sym;
 
 declare_lint! {
+    /// The `array_into_iter` lint detects calling `into_iter` on arrays.
+    ///
+    /// ### Example
+    ///
+    /// ```rust
+    /// # #![allow(unused)]
+    /// [1, 2, 3].into_iter().for_each(|n| { *n; });
+    /// ```
+    ///
+    /// {{produces}}
+    ///
+    /// ### Explanation
+    ///
+    /// In the future, it is planned to add an `IntoIter` implementation for
+    /// arrays such that it will iterate over *values* of the array instead of
+    /// references. Due to how method resolution works, this will change
+    /// existing code that uses `into_iter` on arrays. The solution to avoid
+    /// this warning is to use `iter()` instead of `into_iter()`.
+    ///
+    /// This is a [future-incompatible] lint to transition this to a hard error
+    /// in the future. See [issue #66145] for more details and a more thorough
+    /// description of the lint.
+    ///
+    /// [issue #66145]: https://github.com/rust-lang/rust/issues/66145
+    /// [future-incompatible]: ../index.md#future-incompatible-lints
     pub ARRAY_INTO_ITER,
     Warn,
     "detects calling `into_iter` on arrays",