add GetReferenceCount

stepmania/src/RageSoundReader_Preload.h

@@ -18,6 +18,7 @@ public:
 	~rc_string();
 	string &get_owned();
 	const string &get() const;
+	int GetReferenceCount() const { return *cnt; }
 };
 
 class RageSoundReader_Preload: public SoundReader
@@ -46,6 +47,10 @@ public:
 	unsigned GetNumChannels() const { return channels; }
 	bool IsStreamingFromDisk() const { return false; }
 
+	/* Return the total number of copies of this sound.  (If 1 is returned,
+	 * this is the last copy.) */
+	int GetReferenceCount() const;
+
 	SoundReader *Copy() const;
 	~RageSoundReader_Preload() { }