[GSoC Proposal] Statically Checked Measurement Units

[Don]

Cristi Cobzarenco wrote:
> First, let me apologize for this very late entry, it's the end 
> of university and it's been a very busy period, I hope you will still 
> consider it.
> 
> Note this email is best read using a fixed font.
> 
> PS: I'm really sorry if this is the wrong mailing list to post and I 
> hope you'll forgive me if that's the case.
> 
> ======= Google Summer of Code Proposal: Statically Checked Units =======
> 
> 
> Abstract
> -------------
> 
> Measurement units allow to statically check the correctness of 
> assignments and expressions at virtually no performance cost and very 
> little extra effort. When it comes to physics the advantages are obvious 
> – if you try to assign a force a variable measuring distance, you've 
> most certainly got a formula wrong somewhere along the way. Also, 
> showing a sensor measurement in gallons on a litre display that keeps 
> track of the remaining fuel of a plane (a big no-no) is easily avoidable 
> with this technique. What this translates is that one more of the many 
> hidden assumptions in source code is made visible: units naturally 
> complement other contract checking techniques, like assertions, 
> invariants and the like. After all the unit that a value is measured in 
> is part of the contract.

This is one of those features that gets proposed frequently in multiple 
languages. It's a great example for metaprogramming. But, are there 
examples of this idea being seriously *used* in production code in ANY 
language?
(For example, does anybody actually use Boost.Unit?)