use index or iterator
i can't detect columns name
@0rangeFox I tried to get coroutines working on MSYS. But ended up either with libc++/stdc++ clash or MSYS not properly supporting clang.
You'll have to wait for GCC 11 landing on MSYS, use visual studio or use Linux/WSL
I do not know how to thank you for your loss of time, but thank you very much for your help, and I will look forward to it.