Merge pull request #12755 from alalek:fix_allocSingleton

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

@@ -142,9 +142,13 @@ namespace cv
 CV_EXPORTS void scalarToRawData(const cv::Scalar& s, void* buf, int type, int unroll_to = 0);
 
 //! Allocate all memory buffers which will not be freed, ease filtering memcheck issues
-template <typename T>
-T* allocSingleton(size_t count) { return static_cast<T*>(fastMalloc(sizeof(T) * count)); }
-}
+CV_EXPORTS void* allocSingletonBuffer(size_t size);
+
+//! Allocate all memory buffers which will not be freed, ease filtering memcheck issues
+template <typename T> static inline
+T* allocSingleton(size_t count = 1) { return static_cast<T*>(allocSingletonBuffer(sizeof(T) * count)); }
+
+} // namespace
 
 #if 1 // TODO: Remove in OpenCV 4.x