Win32.memcpy Error in Watershed Image Segmentation

Question

I am trying to implement watershed image segmentation as said by former programmer in :

Watershed using c# or c++

I tried adding FilterGrayToGray.cs code too but i got error of win32.memcpy

The error shows: "The name win32 doesn't exists in this context"

if we convert Win32.memcpy to Microsoft.Win32.memcpy then it says "memcpy doesn't exists in the namespace"