modify code

[rust.git] / clippy_lints / src / undropped_manually_drops.rs

diff --git a/clippy_lints/src/undropped_manually_drops.rs b/clippy_lints/src/undropped_manually_drops.rs
index f4f5e1233e3512ec62ac53e1cbe489c9cc836708..7557e14d11f526917b8faa0da05a3e941c829896 100644 (file)
--- a/clippy_lints/src/undropped_manually_drops.rs
+++ b/clippy_lints/src/undropped_manually_drops.rs
@@ -6,15 +6,17 @@
 use rustc_session::{declare_lint_pass, declare_tool_lint};
 
 declare_clippy_lint! {
-    /// **What it does:** Prevents the safe `std::mem::drop` function from being called on `std::mem::ManuallyDrop`.
+    /// ### What it does
+    /// Prevents the safe `std::mem::drop` function from being called on `std::mem::ManuallyDrop`.
     ///
-    /// **Why is this bad?** The safe `drop` function does not drop the inner value of a `ManuallyDrop`.
+    /// ### Why is this bad?
+    /// The safe `drop` function does not drop the inner value of a `ManuallyDrop`.
     ///
-    /// **Known problems:** Does not catch cases if the user binds `std::mem::drop`
+    /// ### Known problems
+    /// Does not catch cases if the user binds `std::mem::drop`
     /// to a different name and calls it that way.
     ///
-    /// **Example:**
-    ///
+    /// ### Example
     /// ```rust
     /// struct S;
     /// drop(std::mem::ManuallyDrop::new(S));
@@ -26,6 +28,7 @@
     ///     std::mem::ManuallyDrop::drop(&mut std::mem::ManuallyDrop::new(S));
     /// }
     /// ```
+    #[clippy::version = "1.49.0"]
     pub UNDROPPED_MANUALLY_DROPS,
     correctness,
     "use of safe `std::mem::drop` function to drop a std::mem::ManuallyDrop, which will not drop the inner value"
@@ -33,10 +36,10 @@
 
 declare_lint_pass!(UndroppedManuallyDrops => [UNDROPPED_MANUALLY_DROPS]);
 
-impl LateLintPass<'tcx> for UndroppedManuallyDrops {
+impl<'tcx> LateLintPass<'tcx> for UndroppedManuallyDrops {
     fn check_expr(&mut self, cx: &LateContext<'tcx>, expr: &'tcx Expr<'_>) {
-        if let Some(args) = match_function_call(cx, expr, &paths::DROP) {
-            let ty = cx.typeck_results().expr_ty(&args[0]);
+        if let Some([arg_0, ..]) = match_function_call(cx, expr, &paths::DROP) {
+            let ty = cx.typeck_results().expr_ty(arg_0);
             if is_type_lang_item(cx, ty, lang_items::LangItem::ManuallyDrop) {
                 span_lint_and_help(
                     cx,