message: let serde check type
diff: @@ -51,7 +51,7 @@ macro_rules! check_useful_json {
  return $e
  }
  let $x: $t = match
  - serde_json::from_str(&$x)
  + serde_json::from_str::<$t>(&$x)
  .map_err(map_err_trace!())
  .map_err(|err|
  CommonError::InvalidStructure(
  