public abstract Mat this[
	int start,
	int end
] { get; set; }

Public MustOverride Default Property Item ( 
	start As Integer,
	end As Integer
) As Mat
	Get
	Set

public:
virtual property Mat^ default[int start, int end] {
	Mat^ get (int start, int end) abstract;
	void set (int start, int end, Mat^ value) abstract;
}

abstract Item : Mat with get, set