[boost] Fw: Interlibrary version cchecking

Subject: [boost] Fw: Interlibrary version cchecking
From: Robert Ramey (ramey_at_[hidden])
Date: 2010-10-18 13:05:15

"Robert Ramey" <ramey_at_[hidden]> wrote in message
news:<hsdfuq$prj$1_at_[hidden]>...
> 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
> 
> 
>