Textbook in PDF format

The book claims "On the Fly". It intends to provide a comprehensive introduction to the relevant features regarding modern C++ (before the 2020s). Readers can choose interesting content according to the following table of contents to learn and quickly familiarize themselves with the new features that are available. Readers should aware that all of these features are not required. It should be learned when you need it.
At the same time, instead of grammar-only, the book introduces the historical background as simple as possible of its technical requirements, which provides great help in understanding why these features come out.
Also, the author would like to encourage that readers should be able to use modern C++ directly in their new projects and migrate their old projects to modern C++ gradually after reading the book