Re: Conditional compilation based on GSL version

[M Joonas Pihlaja <jpihlaja@cc.helsinki.fi>]

On Fri, 20 Feb 2009, Brian Gough wrote:

> At Thu, 19 Feb 2009 23:04:40 +0200 (EET),
> M Joonas Pihlaja wrote:
> > Could GSL expose some facility in gsl_version.h to compare the version 
> > of GSL at compile time for dumb clients which don't want to impose 
> > special build system requirements?  

> I'd say the GNU approach to compatibility is to test for the 
> presence of individual functions or features with autoconf, rather 
> than package versions--it is more reliable in the long-term.  

Where to draw the line though?  Should I check for the availability of 
every single symbol I'm using from GSL?  Just the ones which I know 
are volatile or new?  *shudder*  Versioning the API is a perfectly 
valid solution to the problem and since GSL does have API stability, 
why not make the version conveniently available to client programs as 
well?

> So if you can use autoconf, I would recommend that.  If not, maybe 
> you could describe the details of the situation a bit more.

Of course.  I won't go into details on why I don't use autoconf for my 
code, but suffice to say that it's about as portable as a pile of 
bricks; doable with enough effort, but really inconvenient and not fun 
at all.  #ifs work everywhere and have a minimal burden when kept 
in check.

The specific situation I'm looking at is simply that GSL implemented 
missing complex vector operations in 1.12 which I'd like to export in 
my GSL <-> Lua minibinding.  Autoconf doesn't even know what Lua is, 
never mind what to do with it. :)

Cheers,

Joonas