Declaring one name per declaration.

CppCoreGuidelines.md

@@ -7880,7 +7880,8 @@ The *always initialize* rule is a style rule aimed to improve maintainability as
 
 Here is an example that is often considered to demonstrate the need for a more relaxed rule for initialization
 
-    widget i, j; // "widget" a type that's expensive to initialize, possibly a large POD
+    widget i;    // "widget" a type that's expensive to initialize, possibly a large POD
+    widget j;
 
     if (cond) {  // bad: i and j are initialized "late"
         i = f1();