public delegate int CvCallback(
	int index,
	IntPtr buffer,
	IntPtr user_data
)

Public Delegate Function CvCallback ( 
	index As Integer,
	buffer As IntPtr,
	user_data As IntPtr
) As Integer

public delegate int CvCallback(
	int index, 
	IntPtr buffer, 
	IntPtr user_data
)

type CvCallback = 
    delegate of 
        index : int * 
        buffer : IntPtr * 
        user_data : IntPtr -> int