"Robert Ramey" <ramey@rrsd.com> wrote in message news:<hsdfuq$prj$1@dough.gmane.org>...
Turns out that the idea of a single boost library deployment has come up a
couple of times here at BoostCon 2010. While preparing my presentation I considered the problem of what would happen if one installed one library which depended on an newer version of a different library than the user already had installed. I actually woke up in the middle of the night imagining someone would ask about that during my talk. I puzzled about it
for some time and the day before I found a way to address it - in my own mind at least. It also seems that it turns out that there are tools that can also manage this.
It's not that I don't trust tools but I wear a belt AND suspenders. So I would like a method which guarentees that when I build one library, I don't accidently include code from a prerequisite library which is a version so old that things won't work. I would also like to know that I'm not accidently running with a DLL built with an old version.
Basically each library includes a file "manifest.hpp". This get's included when any header get's includes (once at most due to include guards). This
includes a static assert that checks that the prequiste libraries are of sufficiently recent version that a dependent library (or user application)
requires. There is also a manifest.cpp file included in the library which
checks any prequiste DLLS. This would be an exheedingly small overhead to
avoid what could be an incredibly large headache.
I just verified that the code compiles so at this point it's only an idea.
But it seems that some kind of check like this is un-avoidable of one want's to deploy libraries as needed rather than as a monolithic distribution.
FYI - no one asked me about this problem at my presentation. Add one more
confirmation of Murphy's law.
Robert Ramey