According to cppcheck there is several places where it advices that znc should use pre-increment/decrement.
If you think that this is false positive and should not be changed, please tell me, so i can report that back to cppcheck in order to get that fixed.
[code]Pre-increment/decrement can be more efficient than post-increment/decrement. Post-increment/decrement usually involves keeping a copy of the previous value around and adds a little extra code.[/code]
In order to save your time i've made tiny patch that does exactly that.