Question

#define cimg_use_jpeg 2

#ifndef cimg_use_jpeg

//code goes here

#endif

I really don’t understand…

Answer 1

Every time things similar to this (so-called impossible things) happen me, the reason is: The code I see in my editor is not the code that runs. This can happen in many ways.

• forgetting to make
• forgetting to save
• saving a copy of the code
• running in a different evironment from the one you compiled to
• the new code ran but I opened and am looking at the old output