eliminate using namespace

src/Map.hh

@@ -456,7 +456,7 @@ public:
     return this->has_any_random_sections;
   }
 
-  // If the map file has no random sections, does nothing and returns a shared_ptr to this. If it has any random
+  // If the map file has no random sections, does nothing and returns a std::shared_ptr to this. If it has any random
   // sections, returns a new map with all non-random sections copied verbatim, and random sections replaced with
   // non-random sections according to the challenge mode enemy generation algorithm.
   std::shared_ptr<MapFile> materialize_random_sections(uint32_t random_seed);