how safe is it to mix ARC and non-ARC code in the same iOS project?

Question

I'm modifying an open source app that is non-ARC. Most of my iOS experience is with ARC enabled objective-c, so when I create and add new files to the project I tend to make them ARC compliant using compiler flags (especially when i'm faced with weird non-arc code bugs).

The thing that keeps me up at night is the question: how safe and reliable is it to mix arc and non-arc code in my project? When QA time comes will it be a nightmare to test for things like memory leaks and performance etc etc? Asked another way.. is it worth converting the existing non-arc code to arc code and get rid of the potential trouble?

Answer 1

You can mix freely without any problems.