Function capture

src/test/common/test_async_spawn_throttle.cc:37–40

}

auto capture(std::optional<std::exception_ptr>& eptr)
{
  return [&eptr] (std::exception_ptr e) { eptr = e; };
}

auto capture(asio::cancellation_signal& signal,
             std::optional<std::exception_ptr>& eptr)