That said, I downloaded their sample pdf and the nice thing is the code they present is very well commented and so it's easy to read. They seem to take a 'read the code to learn the subject' approach, which I appreciate. Note that it takes a slightly conservative approach:
> "Only the passage of time can distill the programming community’s practical experience with each feature and how well it fared, which is why this book discusses features added up to C++14, even though C++20 is already out."
Maybe I'm missing something but they don't seem to offer the book as a searchable PDF? There seems to be a Kindle edition and paperback only. Worried about piracy or something? Otherwise it might be a useful reference, I guess.