checking for optional dependencies

I'm looking for some sample code on how to best check for an optional dependencies (like gstreamer or some other lib) and set a compilation flag like -DMYLIB_HAVE_GSTREAMER. I'm not exactly which one of these functions or how to use them to do this, so any pointers to a sample is much

Re: checking for optional dependencies

Hi Wesley, * Wesley Smith wrote on Tue, Jun 29, 2010 at 02:52:38PM CEST: I'm looking for some sample code on how to best check for an optional dependencies (like gstreamer or some other lib) and set a compilation flag like -DMYLIB_HAVE_GSTREAMER. I'm not exactly which one of these functions