[TypeConverterAttribute(typeof(RectDConverter))]
public struct RectD : IRectangle, ISize, 
	IPoint

<TypeConverterAttribute(GetType(RectDConverter))> _
Public Structure RectD _
	Implements IRectangle, ISize, IPoint

This struct differs from other possible implementation in the way negative Width and Height properties are handled and interpreted. Width and/or height values may be negative in which case the rectangle is considered empty and non-existent. Empty rectangles are not considered in union-like operations, whereas rectangles with Width and Height of 0.0d are. This struct implements the IRectangle interface so that it can be used in methods that require that interface.