lazy log module

gistfile1.cpp

class LazyLogModule
{
public:
  MOZ_CONSTEXPR LazyLogModule(const char* aLogName)
    : mLogName(aLogName), mLog(nullptr)
  {}

  operator LogModule*()
  {
     // Carefully, atomically, instantiate a LogModule* if not already
     // instantiated and return it.
  }

private:
  const char* mLogName;
  LogModule* mLog;
};

LazyLogModule sNetworkingLog("Networking");

// Later on...

MOZ_LOG(sNetworkingLog, ...);