Replace raw pointers => smart pointers (mavlink#314)

Smart pointers provide automatic resource management. In other words,
they implement "Resource Acquisition Is Initialialization programming idiom".
The main goal of this idiom is to ensure that resource acquisition occurs
at the same time that the object is initialized, so that all resources
for the object are created and made ready in one line of code.

`std::unique_ptr` is a smart pointer that owns and manages another object
through a pointer and disposes of that object when the unique_ptr goes out of scope.

Ref 1: https://docs.microsoft.com/en-us/cpp/cpp/smart-pointers-modern-cpp
Ref 2: http://en.cppreference.com/w/cpp/memory/unique_ptr

core/dronecore.cpp

@@ -6,15 +6,12 @@
 namespace dronecore {
 
 DroneCore::DroneCore() :
-    _impl(nullptr)
+    _impl { new DroneCoreImpl() }
 {
-    _impl = new DroneCoreImpl();
 }
 
 DroneCore::~DroneCore()
 {
-    delete _impl;
-    _impl = nullptr;
 }
 
 ConnectionResult DroneCore::add_any_connection(const std::string &connection_url)

core/dronecore.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <string>
+#include <memory>
 #include <vector>
 #include <functional>
 
@@ -174,7 +175,7 @@ class DroneCore
 
 private:
     /* @private. */
-    DroneCoreImpl *_impl;
+    std::unique_ptr<DroneCoreImpl> _impl;
 
     // Non-copyable
     DroneCore(const DroneCore &) = delete;

plugins/action/action.cpp

@@ -4,14 +4,13 @@
 namespace dronecore {
 
 Action::Action(Device &device) :
-    PluginBase()
+    PluginBase(),
+    _impl { new ActionImpl(device) }
 {
-    _impl = new ActionImpl(device);
 }
 
 Action::~Action()
 {
-    delete _impl;
 }
 
 Action::Result Action::arm() const

plugins/action/action.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <functional>
+#include <memory>
 #include "plugin_base.h"
 
 namespace dronecore {
@@ -281,7 +282,7 @@ class Action : public PluginBase
 
 private:
     /** @private Underlying implementation, set at instantiation */
-    ActionImpl *_impl;
+    std::unique_ptr<ActionImpl> _impl;
 };
 
 } // namespace dronecore

plugins/follow_me/follow_me.cpp

@@ -4,14 +4,13 @@
 namespace dronecore {
 
 FollowMe::FollowMe(Device &device) :
-    PluginBase()
+    PluginBase(),
+    _impl { new FollowMeImpl(device) }
 {
-    _impl = new FollowMeImpl(device);
 }
 
 FollowMe::~FollowMe()
 {
-    delete _impl;
 }
 
 const FollowMe::Config &FollowMe::get_config() const

plugins/follow_me/follow_me.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <string>
+#include <memory>
 #include <iostream>
 #include <cmath>
 #include <functional>
@@ -188,7 +189,7 @@ class FollowMe : public PluginBase
 
 private:
     // Underlying implementation, set at instantiation
-    FollowMeImpl *_impl;
+    std::unique_ptr<FollowMeImpl> _impl;
 };
 
 } // namespace dronecore

plugins/gimbal/gimbal.cpp

@@ -4,14 +4,13 @@
 namespace dronecore {
 
 Gimbal::Gimbal(Device &device) :
-    PluginBase()
+    PluginBase(),
+    _impl { new GimbalImpl(device) }
 {
-    _impl = new GimbalImpl(device);
 }
 
 Gimbal::~Gimbal()
 {
-    delete _impl;
 }
 
 Gimbal::Result Gimbal::set_pitch_and_yaw(float pitch_deg, float yaw_deg)

plugins/gimbal/gimbal.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <functional>
+#include <memory>
 #include "plugin_base.h"
 
 namespace dronecore {
@@ -95,7 +96,7 @@ class Gimbal : public PluginBase
 
 private:
     /** @private Underlying implementation, set at instantiation */
-    GimbalImpl *_impl;
+    std::unique_ptr<GimbalImpl> _impl;
 };
 
 } // namespace dronecore

plugins/info/info.cpp

@@ -4,14 +4,13 @@
 namespace dronecore {
 
 Info::Info(Device &device) :
-    PluginBase()
+    PluginBase(),
+    _impl { new InfoImpl(device) }
 {
-    _impl = new InfoImpl(device);
 }
 
 Info::~Info()
 {
-    delete _impl;
 }
 
 uint64_t Info::uuid() const

plugins/info/info.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <cstdint>
+#include <memory>
 #include "plugin_base.h"
 
 namespace dronecore {
@@ -108,7 +109,7 @@ class Info : public PluginBase
 
 private:
     /** @private Underlying implementation, set at instantiation */
-    InfoImpl *_impl;
+    std::unique_ptr<InfoImpl> _impl;
 };
 
 } // namespace dronecore

plugins/logging/logging.cpp

@@ -4,14 +4,13 @@
 namespace dronecore {
 
 Logging::Logging(Device &device) :
-    PluginBase()
+    PluginBase(),
+    _impl { new LoggingImpl(device) }
 {
-    _impl = new LoggingImpl(device);
 }
 
 Logging::~Logging()
 {
-    delete _impl;
 }
 
 Logging::Result Logging::start_logging() const

plugins/logging/logging.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <functional>
+#include <memory>
 #include "plugin_base.h"
 
 namespace dronecore {
@@ -108,7 +109,7 @@ class Logging : public PluginBase
 
 private:
     /** @private Underlying implementation, set at instantiation */
-    LoggingImpl *_impl;
+    std::unique_ptr<LoggingImpl> _impl;
 };
 
 } // namespace dronecore

plugins/mission/mission.cpp

@@ -6,14 +6,13 @@
 namespace dronecore {
 
 Mission::Mission(Device &device) :
-    PluginBase()
+    PluginBase(),
+    _impl { new MissionImpl(device) }
 {
-    _impl = new MissionImpl(device);
 }
 
 Mission::~Mission()
 {
-    delete _impl;
 }
 
 

plugins/mission/mission.h

@@ -206,7 +206,7 @@ class Mission : public PluginBase
 
 private:
     /** @private Underlying implementation, set at instantiation */
-    MissionImpl *_impl;
+    std::unique_ptr<MissionImpl> _impl;
 };
 
 } // namespace dronecore

plugins/mission/mission_item.cpp

@@ -5,13 +5,12 @@
 namespace dronecore {
 
 MissionItem::MissionItem() :
-    _impl(new MissionItemImpl())
+    _impl { new MissionItemImpl() }
 {
 }
 
 MissionItem::~MissionItem()
 {
-    delete _impl;
 }
 
 

plugins/mission/mission_item.h

@@ -1,5 +1,6 @@
 #pragma once
 #include <string>
+#include <memory>
 
 namespace dronecore {
 
@@ -197,7 +198,7 @@ class MissionItem
 
 private:
     /** @private Underlying implementation, set at instantiation */
-    MissionItemImpl *_impl;
+    std::unique_ptr<MissionItemImpl> _impl;
 };
 
 } // namespace dronecore

plugins/offboard/offboard.cpp

@@ -4,14 +4,13 @@
 namespace dronecore {
 
 Offboard::Offboard(Device &device) :
-    PluginBase()
+    PluginBase(),
+    _impl { new OffboardImpl(device) }
 {
-    _impl = new OffboardImpl(device);
 }
 
 Offboard::~Offboard()
 {
-    delete _impl;
 }
 
 Offboard::Result Offboard::start()

plugins/offboard/offboard.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <functional>
+#include <memory>
 #include "plugin_base.h"
 
 namespace dronecore {
@@ -163,7 +164,7 @@ class Offboard : public PluginBase
 
 private:
     /** @private Underlying implementation, set at instantiation */
-    OffboardImpl *_impl;
+    std::unique_ptr<OffboardImpl> _impl;
 };
 
 } // namespace dronecore