Getting width of word in new UI system: GetCharacterInfo?

I need to get the rendered width of a word (InputField or Text object) in the new UI system (4.6), to implement my own word-wrapping system. (Aside: the built in system will split a long word in the middle if it has to, but I want to shrink the font instead.)

The first two lines of my code (JavaScript/UnityScript) run without error. The third line is the problem:

 var ci : CharacterInfo;
 dotFont.GetCharacterInfo( "T"[0], ci, 32 ); //Font size 32
 Debug.Log (ci.advance);

I want it to tell me the rendered width of a capital letter "T" at 32-point size. (dotFont is assigned in the Inspector, and renders fine visually.)

But I get this error: BCE0019: 'advance' is not a member of 'UnityEngine.CharacterInfo'.

Same error if I try "glyphWidth" instead of "advance". But those are all listed here:

http://docs.unity3d.com/ScriptReference/CharacterInfo.html

What might I be doing wrong? How can I access CharacterInfo details properly from JavaScript? (Or is there a better approach to getting the width of a word? My last resort will be to measure the characters in Photoshop and make my own LUT. Yuck!)

Thanks in advance! (No pun intended.)