What do you mean by "modern C++"? C++11, C++14 or C++17? There are older book that a word "modern" on a cover, but they cover old-style C++ with template meta-p

What do you mean by "modern C++"? C++11, C++14 or C++17? There are older book that a word "modern" on a cover, but they cover old-style C++ with template meta-programming.