What is the level of the material contained in the book Data Structures and Algorithm Analysis in C++ (4th Ed) by Weiss?
Once I skimmed through a dozen of textbooks, looking for ones better explaining sorting and data structures (i.e. no graphs, string algos and so on).

Weiss was the best one according to my criteria. In particular, it describes more advanced techniques for hash tables, which are heart of most real use cases. Although even this book doesn't include Robin Hood hashing - learn it from Wikipedia pointers.

More info: https://www.quora.com/How-do-I-learn-data-structure-and-algorithm-in-C++-I-know-the-basics-by-myself-Can-you-suggest-any-e-books-for-me-to-use/answer/Bulat-Ziganshin

Another extremely important topic: https://www.quora.com/What-are-good-resources-to-learn-concurrent-programming-in-C++/answer/Bulat-Ziganshin