[Interest] QRegExp help: boundaries

[Sensei]

Dear all,

I am trying to use QRegExp to find if a string contains a latex command, 
but I'm puzzled on how to do that.

In particular, for those who don't know latex, commands are (simplifying 
a lot) words starting with a backslash \ and using curly parentheses {} 
(and brackets []). For example

     \documentclass[11pt]{article}

Now, I'd like to find that command. I wanted to use a QRegExp, in 
particular this code:

     if (s.indexOf(QRegExp("\b\\\\documentclass\b")) > -1)

However, I get no luck with word boundaries. In fact, a string like the 
one I wrote as an example of latex, isn't recognized. I need word 
boundaries because I want to discern between

     \documentclass{article} <--- GOOD
     \documentclasss{article} <-- BAD
     \documentclass {article} <-- GOOD
     etc.

Any hint? I'm not THAT familiar with regexps, though!


Thanks & Cheers!