They are already defined in the forward decleration header and defining them
more than once will give an error with OSX's clang about typedef redefinition
being a C11 feature.
G_BEGIN_DECLS
-typedef struct _GstGLSLStage GstGLSLStage;
-typedef struct _GstGLSLStageClass GstGLSLStageClass;
-typedef struct _GstGLSLStagePrivate GstGLSLStagePrivate;
-
#define GST_TYPE_GLSL_STAGE (gst_glsl_stage_get_type())
#define GST_GLSL_STAGE(o) (G_TYPE_CHECK_INSTANCE_CAST((o), GST_TYPE_GLSL_STAGE, GstGLSLStage))
#define GST_GLSL_STAGE_CLASS(k) (G_TYPE_CHECK_CLASS((k), GST_TYPE_GLSL_STAGE, GstGLSLStageClass))