I needed this to compile OpenNI2-2.0.0.30 with XCode's g++.

openni2-gcc44.patch

# possible workaround for https://github.com/OpenNI/OpenNI2/issues/11
# as of OpenNI2-2.0.0.30

diff --git a/Source/Drivers/PS1080/DDK/XnDeviceBase.h b/Source/Drivers/PS1080/DDK/XnDeviceBase.h
index c9e740b..5d7cc79 100644
--- a/Source/Drivers/PS1080/DDK/XnDeviceBase.h
+++ b/Source/Drivers/PS1080/DDK/XnDeviceBase.h
@@ -101,7 +101,9 @@ public:
        virtual XnStatus UnregisterFromPropertyChange(const XnChar* Module, XnUInt32 propertyId, XnCallbackHandle hCallback);
 
        typedef xnl::Event<XnNewStreamDataEventArgs> NewStreamDataEvent;
-       NewStreamDataEvent::EventInterface& OnNewStreamDataEvent() { return m_OnNewStreamDataEvent; }
+       // gcc-4.4 can't handle this, so return the subclass, seems to work?
+       //NewStreamDataEvent::EventInterface& OnNewStreamDataEvent() { return m_OnNewStreamDataEvent; }
+       NewStreamDataEvent& OnNewStreamDataEvent() { return m_OnNewStreamDataEvent; }
 
        /**
        * Finds a stream (a module which has the IS_STREAM property set to TRUE). 
--- OpenNI2-2.0.0.30/Source/Drivers/PSLink/LinkProtoLib/XnLinkFrameInputStream.h.old    2013-09-25 09:00:11.000000000 -0700
+++ OpenNI2-2.0.0.30/Source/Drivers/PSLink/LinkProtoLib/XnLinkFrameInputStream.h        2013-09-25 09:02:03.000000000 -0700
@@ -49,7 +49,11 @@
        virtual XnStreamFragLevel GetStreamFragLevel() const { return XN_LINK_STREAM_FRAG_LEVEL_FRAMES; }
 
        typedef void (XN_CALLBACK_TYPE* NewFrameEventHandler)(const NewFrameEventArgs& args, void* pCookie);
-       NewFrameEvent::EventInterface& GetNewFrameEvent() { return m_newFrameEvent; }
+        // gcc-4.4 can't handle this, so return the subclass, seems to work?
+        // Avoids error
+        // LinkProtoLib/XnLinkFrameInputStream.h:52: error: type ‘xnl::Event<xn::NewFrameEventArgs>’ is not derived from type ‘xn::LinkFrameInputStream’
+       //NewFrameEvent::EventInterface& GetNewFrameEvent() { return m_newFrameEvent; }
+       NewFrameEvent& GetNewFrameEvent() { return m_newFrameEvent; }
 
        virtual XnBool IsOutputFormatSupported(OniPixelFormat format) const;