docs: update code-style rule 2.24

This commit also updates existing code to use the new format.

refs #4681

Change-Id: I88e62a34fc55a69cd01d74e80a7000c6cf4d7c2d
diff --git a/src/name.hpp b/src/name.hpp
index 2fd48a0..ad986d7 100644
--- a/src/name.hpp
+++ b/src/name.hpp
@@ -42,15 +42,7 @@
 class Name
 {
 public: // nested types
-  class Error : public name::Component::Error
-  {
-  public:
-    explicit
-    Error(const std::string& what)
-      : name::Component::Error(what)
-    {
-    }
-  };
+  using Error = name::Component::Error;
 
   using Component = name::Component;
   using component_container = std::vector<Component>;