message: Explicitly default-initialize temporary in apply()
diff: @@ -473,7 +473,7 @@ public:
  return apply(dur);
  }
  if (Derived::writes_state) {
  - Duration dur;
  + Duration dur{};
  auto e = apply(dur);
  t = std::chrono::time_point<std::chrono::system_clock, Duration>{dur};
  return e;
  