fixed compilation under Ubuntu without CUDA

modules/gpu/src/precomp.hpp

@@ -123,9 +123,18 @@
     static inline void throw_nogpu() { CV_Error(CV_StsNotImplemented, "The called functionality is disabled for current build or platform"); }
 
 #else /* defined(HAVE_CUDA) */
-
+    
     static inline void throw_nogpu() { CV_Error(CV_GpuNotSupported, "The library is compiled without GPU support"); }
 
 #endif /* defined(HAVE_CUDA) */
 
+
+namespace cv { namespace gpu 
+{
+    // Converts CPU border extrapolation mode into GPU internal analogue.
+    // Returns true if the GPU analogue exists, false otherwise.
+    bool tryConvertToGpuBorderType(int cpuBorderType, int& gpuBorderType);
+
+}}
+
 #endif /* __OPENCV_PRECOMP_H__ */