upd: remove nullptr from return value

src/names.cpp

@@ -62,7 +62,7 @@ std::any FucntionContainer::CallFunction(const std::string &name,
         std::cout << std::fixed << std::setprecision(6) << *value_ptr;
     }
     std::cout << '\n';
-    return nullptr;
+    return NoneType();
   } else if (name == "str") {
     if (args.size() != 1)
       throw InterpretException(