Detailed structure checks

[Tim Post]

Hello,

I have been looking for a macro that will allow me to test to see if a
structure exists in a header, and if it has a particular member. I'm
writing things that depend on external libraries that are still 'moving
targets'.

For instance, if a library exposes struct foo { , I need to see if foo
has a member named bar.

I've been looking around for a day or two, but can't seem to locate a
generic macro that would be suitable... or I'm just flat out missing it
in the autoconf manual. This could be the case, I think I've gone a
little snow blind while looking.

I wanted to ask this list prior to trying to write one myself.

Thanks in advance for any replies :)

Cheers,
--Tim