Question

I have quite a large piece of code, that works well in a development version, with many assert() in the code. I disabled assertions with -DNDEBUG directive passed to g++, and now my code breaks with seg. fault. Is there something I don’t know about assert()?

Answer 1

The most common issue with assert to my knowledge is having code with side effects within the assert itself. When you compile with -DNDEBUG asserts are essentially commented out, and thus code inside the assert isn’t executed. The assert man page mentions this in the bugs section:

BUGS
       assert()  is implemented as a macro; if the expression tested has side-
       effects, program behavior will be different depending on whether NDEBUG
       is defined.  This may create Heisenbugs which go away when debugging is
       turned on.