Expose BufferPool class for external use also

modules/core/include/opencv2/core/cuda.hpp

@@ -327,6 +327,34 @@ The function does not reallocate memory if the matrix has proper attributes alre
  */
 CV_EXPORTS void ensureSizeIsEnough(int rows, int cols, int type, OutputArray arr);
 
+/** @brief BufferPool for use with CUDA streams
+
+ * BufferPool utilizes cuda::Stream's allocator to create new buffers. It is
+ * particularly useful when BufferPoolUsage is set to true, or a custom
+ * allocator is specified for the cuda::Stream, and you want to implement your
+ * own stream based functions utilizing the same underlying GPU memory
+ * management.
+ */
+class CV_EXPORTS BufferPool
+{
+public:
+
+    //! Gets the BufferPool for the given stream.
+    explicit BufferPool(Stream& stream);
+
+    //! Allocates a new GpuMat of given size and type.
+    GpuMat getBuffer(int rows, int cols, int type);
+
+    //! Allocates a new GpuMat of given size and type.
+    GpuMat getBuffer(Size size, int type) { return getBuffer(size.height, size.width, type); }
+
+    //! Returns the allocator associated with the stream.
+    Ptr<GpuMat::Allocator> getAllocator() const { return allocator_; }
+
+private:
+    Ptr<GpuMat::Allocator> allocator_;
+};
+
 //! BufferPool management (must be called before Stream creation)
 CV_EXPORTS void setBufferPoolUsage(bool on);
 CV_EXPORTS void setBufferPoolConfig(int deviceId, size_t stackSize, int stackCount);

modules/core/include/opencv2/core/private.cuda.hpp

@@ -102,20 +102,6 @@ static inline void throw_no_cuda() { CV_Error(cv::Error::StsNotImplemented, "The
 
 namespace cv { namespace cuda
 {
-    class CV_EXPORTS BufferPool
-    {
-    public:
-        explicit BufferPool(Stream& stream);
-
-        GpuMat getBuffer(int rows, int cols, int type);
-        GpuMat getBuffer(Size size, int type) { return getBuffer(size.height, size.width, type); }
-
-        GpuMat::Allocator* getAllocator() const { return allocator_; }
-
-    private:
-        GpuMat::Allocator* allocator_;
-    };
-
     static inline void checkNppError(int code, const char* file, const int line, const char* func)
     {
         if (code < 0)