Remove direct struct access from usage of the Hamlib API

Preparation for safe dynamic linking to Hamlib where minor Hamlib
upgrades can be deployed just by replacing the DLL/SO.

Transceiver/HamlibTransceiver.hpp

@@ -1,14 +1,11 @@
 #ifndef HAMLIB_TRANSCEIVER_HPP_
 #define HAMLIB_TRANSCEIVER_HPP_
 
-#include <tuple>
-
 #include <QString>
 
-#include <hamlib/rig.h>
-
 #include "TransceiverFactory.hpp"
 #include "PollingTransceiver.hpp"
+#include "pimpl_h.hpp"
 
 // hamlib transceiver and PTT mostly delegated directly to hamlib Rig class
 class HamlibTransceiver final
@@ -20,10 +17,11 @@ public:
   static void register_transceivers (logger_type *, TransceiverFactory::Transceivers *);
   static void unregister_transceivers ();
 
-  explicit HamlibTransceiver (logger_type *, int model_number, TransceiverFactory::ParameterPack const&,
+  explicit HamlibTransceiver (logger_type *, unsigned model_number, TransceiverFactory::ParameterPack const&,
                               QObject * parent = nullptr);
   explicit HamlibTransceiver (logger_type *, TransceiverFactory::PTTMethod ptt_type, QString const& ptt_port,
                               QObject * parent = nullptr);
+  ~HamlibTransceiver ();
 
 private:
   int do_start () override;
@@ -35,38 +33,8 @@ private:
 
   void do_poll () override;
 
-  void error_check (int ret_code, QString const& doing) const;
-  void set_conf (char const * item, char const * value);
-  QByteArray get_conf (char const * item);
-  Transceiver::MODE map_mode (rmode_t) const;
-  rmode_t map_mode (Transceiver::MODE mode) const;
-  std::tuple<vfo_t, vfo_t> get_vfos (bool for_split) const;
-
-  struct RIGDeleter {static void cleanup (RIG *);};
-  QScopedPointer<RIG, RIGDeleter> rig_;
-
-  bool ptt_only_;               // we can use a dummy device for PTT
-  bool back_ptt_port_;
-  bool one_VFO_;
-  bool is_dummy_;
-
-  // these are saved on destruction so we can start new instances
-  // where the last one left off
-  static freq_t dummy_frequency_;
-  static rmode_t dummy_mode_;
-
-  bool mutable reversed_;
-
-  bool freq_query_works_;
-  bool mode_query_works_;
-  bool split_query_works_;
-  bool tickle_hamlib_;          // Hamlib requires a
-                                // rig_set_split_vfo() call to
-                                // establish the Tx VFO
-  bool get_vfo_works_;          // Net rigctl promises what it can't deliver
-  bool set_vfo_works_;          // More rigctl promises which it can't deliver
-
-  static int debug_callback (enum rig_debug_level_e level, rig_ptr_t arg, char const * format, va_list ap);
+  class impl;
+  pimpl<impl> m_;
 };
 
 #endif