Hi,

I've been updating my perl wrapper for zxing-cpp and in general it works.

Unfortunately if I build zxing-cpp 2.3.0 with -DZXING_EXPERIMENTAL_API my barcode reader tests fail, either with a segmentation fault or a double free.

After a fair amount of debugging it seems like the types I see in my calling code are different to the types seen in the library presumably due to the class layout changes that ZXING_EXPERIMENTAL_API causes.

If I manually define ZXING_EXPERIMENTAL_API when building my code things work - but I don't see a way to detect that manually, the macro is defined neither in zxing.pc nor in Version.h.

Is there another way downstream users should be able to check whether the library was built with ZXING_EXPERIMENTAL_API?