[boost] Where is boost/detail/limits.hpp used?

Subject: [boost] Where is boost/detail/limits.hpp used?
From: Peter Dimov (lists_at_[hidden])
Date: 2014-02-10 08:17:20

I'm playing with a dependency checker I wrote that tells me what Boost 
module depends on what. Starting with the basics:

Dependencies for config:

detail:
        boost/detail/endian.hpp

A dependency from config to detail is not a good thing because detail 
depends on too much.

boost/detail/endian.hpp is now only a forwarding header to predef, so it 
could and probably should be moved to predef, which seems to depend on 
nothing.

But I was wondering what in config uses endian.hpp. Turns out the only use 
is in boost/detail/limits.hpp, a file that has been put into config for some 
reason. I can't find anything in config or in Boost that uses this file. 
What is its purpose?