 /**
 Returns a rectangle with a positive width and height.
 
+    let r = C4Rect(0.1,0.1,10.6,10.6)
+    integral(r) //-> {0,0,11,11}
+
 :param: rect	The source rectangle.
 :returns:	A rectangle that represents the source rectangle, but with positive width and height values.
 */


/**
Returns the smallest rectangle that contains the two source rectangles.

:param: r1	The first source rectangle.
:param: r2	The second source rectangle.

//MARK: - Manipulating
/**
Returns the intersection of two rectangles.

    let r1 = C4Rect(0,0,10,10)
    let r2 = C4Rect(5,5,10,10)
    intersection(r1,r2) //-> {5,5,5,5}

:param: rect1	The first source rectangle.
:param: rect2	The second source rectangle.
