Question

I am creating a c++ program that can use GDAL (if present). I can check the presence of GDAL in the system but how I need to code my program to include/not include the GDAL libraries if my program was compiled using GDAL?

Many thanks,
Carlos.

Answer 1

While I haven’t used CMake, but if the library is available you can link with it and also pass a flag to the compiler defining a macro (e.g. -DHAVE_GDAL). Then in your source you use the preprocessor to check for HAVE_GDAL and only use GDAL functionality if it’s defined.

Something like this in your source:

#ifdef HAVE_GDAL
// Use GDAL functionality
#else
// Use something else
#endif