add example

bin/main.cpp

@@ -88,6 +88,7 @@ int main(int argc, char *argv[])
     hack::container::vector_multiset(v, "asdf", "qwer", "zcv");
     // of course you understand that a new logger object is created here every time !!!
     for(const auto& c : v) hack::log()(c);
+    hack::log()(v);
   }
 
   hack::log()("============================================================");