Get rid of unnecessary cast of FlexfecReceiveStreamImpl to FlexfecReceiveStream

webrtc/call/flexfec_receive_stream_impl.h

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 22 matching lines @@
                                  public RtpPacketSinkInterface {
  public:
   FlexfecReceiveStreamImpl(
       RtpStreamReceiverControllerInterface* receiver_controller,
       const Config& config,
       RecoveredPacketReceiver* recovered_packet_receiver,
       RtcpRttStats* rtt_stats,
       ProcessThread* process_thread);
   ~FlexfecReceiveStreamImpl() override;
 
-  const Config& GetConfig() const { return config_; }
-
   // RtpPacketSinkInterface.
   void OnRtpPacket(const RtpPacketReceived& packet) override;
 
   // Implements FlexfecReceiveStream.
   void Start() override;
   void Stop() override;
   Stats GetStats() const override;
 
+  const Config& GetConfig() const override;

[eladalon, 2017/07/04 09:56:26]

Might also be a good idea to return a copy of the Config, rather than a
reference to it. Otherwise, we have no guarantee nobody would be using it past
its lifetime. (Separate issue for a separate CL, though.) What do you think?

[ossu, 2017/07/21 13:07:15]

IMO, there's no reason to return a copy unless access to the Config must be
serialized (thus necessitating a serialized copy in GetConfig()). Nobody should
keep references inside other objects around. If the caller needs to retain a
Config, it's super easy for them to copy it during the GetConfig() call (or
later).

[eladalon, 2017/07/21 13:19:31]

I was thinking about fool-proofing it, but I guess you're right - if returning a
temporarily valid handle is good enough for the STL (std::string::c_str), it
should be good enough for me; copying comes at a price, after all.

+
  private:
   // Config.
   const Config config_;
   bool started_ GUARDED_BY(crit_);
   rtc::CriticalSection crit_;
 
   // Erasure code interfacing.
   const std::unique_ptr<FlexfecReceiver> receiver_;
 
   // RTCP reporting.
   const std::unique_ptr<ReceiveStatistics> rtp_receive_statistics_;
   const std::unique_ptr<RtpRtcp> rtp_rtcp_;
   ProcessThread* process_thread_;
 
   std::unique_ptr<RtpStreamReceiverInterface> rtp_stream_receiver_;
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_CALL_FLEXFEC_RECEIVE_STREAM_IMPL_H_