I am slowly crawling through the high-priority header files, as defined in the spreadsheet. Some of them can be really time-consuming, I think I spent over two days on str.h. A huge chunk of this time is spent on reading, googling, and expanding my knowledge of C++: how to understand operator functions, how iterators work, streams, arrays, lists, strings...I'm surely learning a lot but it annoys that it takes so much time that is then not really reflected in the work I'm submitting.
The problem I am already starting to see is that reviewing my PRs will take quite a bit of time. Every doxygen comment that I am adding there needs to verified, simply because my understanding of the function/type/attribute might have been wrong. And as my PRs are getting verified, the header files that they are massively editing are being changed on master by other developers, which produces some nasty merge conflicts. I guess fighting merge conflicts might become one of the main challenges in the remaining part of the project.
I'm going back to my files, you can track my progress in the Google spreadsheet if you are interested. I usually put a green 'Reviewed' field next to the files that I have already gone through and included in a PR.