Index: /trunk/include/VBox/vmm/pdmaudioifs.h
===================================================================
--- /trunk/include/VBox/vmm/pdmaudioifs.h	(revision 64878)
+++ /trunk/include/VBox/vmm/pdmaudioifs.h	(revision 64879)
@@ -326,4 +326,15 @@
 
 /**
+ * Union for keeping an audio stream destination or source.
+ */
+typedef union PDMAUDIODESTSOURCE
+{
+    /** Desired playback destination (for an output stream). */
+    PDMAUDIOPLAYBACKDEST Dest;
+    /** Desired recording source (for an input stream). */
+    PDMAUDIORECSOURCE    Source;
+} PDMAUDIODESTSOURCE, *PPDMAUDIODESTSOURCE;
+
+/**
  * Structure for keeping an audio stream configuration.
  */
@@ -334,11 +345,6 @@
     /** Direction of the stream. */
     PDMAUDIODIR              enmDir;
-    union
-    {
-        /** Desired playback destination (for an output stream). */
-        PDMAUDIOPLAYBACKDEST Dest;
-        /** Desired recording source (for an input stream). */
-        PDMAUDIORECSOURCE    Source;
-    } DestSource;
+    /** Destination / source indicator, depending on enmDir. */
+    PDMAUDIODESTSOURCE       DestSource;
     /** Frequency in Hertz (Hz). */
     uint32_t                 uHz;