[boost] [chrono] patch for VC9 duration conversions

Subject: [boost] [chrono] patch for VC9 duration conversions
From: David Deakins (ddeakins_at_[hidden])
Date: 2011-02-23 01:30:57

Currently the enable_if expressions that restrict implicit duration type 
conversion to only conversions that will not reduce resolution are 
disabled on VC9 because they trigger a compiler error.  I have come up 
with a slight adjustment to the expression that VC9 appears to be able 
to digest more favorably.  Attached is a patch.  I also opened ticket 
5214 in Trac with this information.  Vincent, if the patch looks good, 
let me know if you want to apply it or if you would like me to.

-Dave