CoreText. How Do I Calculate the Bounding Box of an Attributed String?

In CoreText it is easy ask: "for a given rectangle how much of this attributed string will fit?".

CTFrameGetVisibleStringRange(rect).length

Will return where in the string the next run of text should begin.

My question is: "given an attributed string and a width, what rect height do I need to completely bound the attributed string?".

Does the CoreText framework provide tools to do this?

Thanks,
Doug