Move shared interface to header file rather than repeating.

modules/cudastereo/src/cuda/disparity_bilateral_filter.cu

@@ -45,6 +45,8 @@
 #include "opencv2/core/cuda/common.hpp"
 #include "opencv2/core/cuda/limits.hpp"
 
+#include "cuda/disparity_bilateral_filter.hpp"
+
 namespace cv { namespace cuda { namespace device
 {
     namespace disp_bilateral_filter

modules/cudastereo/src/cuda/disparity_bilateral_filter.hpp

+namespace cv { namespace cuda { namespace device
+{
+    namespace disp_bilateral_filter
+    {
+        template<typename T>
+        void disp_bilateral_filter(PtrStepSz<T> disp, PtrStepSzb img, int channels, int iters, const float *, const float *, size_t, int radius, short edge_disc, short max_disc, cudaStream_t stream);
+    }
+}}}

modules/cudastereo/src/disparity_bilateral_filter.cpp

@@ -51,14 +51,7 @@ Ptr<cuda::DisparityBilateralFilter> cv::cuda::createDisparityBilateralFilter(int
 
 #else /* !defined (HAVE_CUDA) */
 
-namespace cv { namespace cuda { namespace device
-{
-    namespace disp_bilateral_filter
-    {
-        template<typename T>
-        void disp_bilateral_filter(PtrStepSz<T> disp, PtrStepSzb img, int channels, int iters, const float *, const float *, size_t, int radius, short edge_disc, short max_disc, cudaStream_t stream);
-    }
-}}}
+#include "cuda/disparity_bilateral_filter.hpp"
 
 namespace
 {