Applying suggested changes from the PR

clippy_lints/src/matches.rs

@@ -1238,18 +1238,20 @@ fn check_match_single_binding<'a>(cx: &LateContext<'a>, ex: &Expr<'a>, arms: &[A
         return;
     }
 
-    // Check that the match doesn't contain other branches that might be excluded by `#[cfg]` or other
-    // macros
-    if let Some(match_snippet) = snippet_opt(cx, expr.span) {
-        if let Some(arm_snippet) = snippet_opt(cx, arms[0].span) {
-            if let Some(ex_snippet) = snippet_opt(cx, ex.span) {
-                let rest_snippet = match_snippet.replace(&arm_snippet, "").replace(&ex_snippet, "");
-                if rest_snippet.contains("=>") {
-                    // The code it self contains another thick arrow "=>"
-                    // -> Either another arm or a comment
-                    return;
-                }
-            }
+    // HACK:
+    // This is a hack to deal with arms that are excluded by macros like `#[cfg]`. It is only used here
+    // to prevent false positives as there is currently no better way to detect if code was excluded by
+    // a macro. See PR #6435
+    if_chain! {
+        if let Some(match_snippet) = snippet_opt(cx, expr.span);
+        if let Some(arm_snippet) = snippet_opt(cx, arms[0].span);
+        if let Some(ex_snippet) = snippet_opt(cx, ex.span);
+        let rest_snippet = match_snippet.replace(&arm_snippet, "").replace(&ex_snippet, "");
+        if rest_snippet.contains("=>");
+        then {
+            // The code it self contains another thick arrow "=>"
+            // -> Either another arm or a comment
+            return;
         }
     }