Added mosra's suggestions

src/ChargeAudio.hpp

@@ -18,21 +18,21 @@ typedef Containers::Pointer<class Sound> SoundContainer;
 typedef Containers::Pointer<class Listener> ListenerContainer;
 class Sound {
 public:
-  enum SoundState { Idle, Playing, Paused, Finished };
+  enum class SoundState { Idle, Playing, Paused, Finished };
 
   ~Sound();
   void Play();
   void Pause();
   void Reset();
 
-  SoundState GetState();
-  float GetPlaybackTime();
+  const SoundState GetState();
+  const float GetPlaybackTime();
   bool SetPlaybackTime(float time);
-  float GetDuration();
+  const float GetDuration();
   void SetPosition(Magnum::Vector3 position);
-  Magnum::Vector3 GetPosition();
+  const Magnum::Vector3 GetPosition();
   void SetVolume(float value);
-  float GetVolume();
+  const float GetVolume();
 
 private:
   Sound(class Engine *engine, std::function<void(Sound *)> setupFunction,
@@ -50,11 +50,11 @@ private:
 class Listener {
 public:
   void SetEnabled(bool isEnabled);
-  bool GetEnabled();
+  const bool GetEnabled();
   void SetDirection(Magnum::Vector3 position);
-  Magnum::Vector3 GetDirection();
+  const Magnum::Vector3 GetDirection();
   void SetPosition(Magnum::Vector3 position);
-  Magnum::Vector3 GetPosition();
+  const Magnum::Vector3 GetPosition();
 
 private:
   Listener();
@@ -73,7 +73,7 @@ public:
   ListenerContainer CreateListener();
 
   void SetVolume(float value);
-  float GetVolume();
+  const float GetVolume();
 
 private:
   ma_engine maEngine;