> OK, great. Now I have a few hundred lines of C++ I need to read through and completely understand to see why it's incorrect.

I think it's often better to just skip this and delete the code. The cool thing about those agents is that the cost of trying this out is extremely cheap, so you don't have to overthink it and if it looks incorrect, just revert it and try something else.

I've been experimenting with Junie for past few days, and had very positive experience. It wrote a bunch of tests for me that I've been postponing for quite some time it was mostly correct from a single sentence prompt. Sometimes it does something incorrect, but I usually just revert it and move on, try something else later. There's definitely a sweet spot for things tasks it does well and you have to experiment a bit to find it out.