"Modern C++" often refers specifically to techniques from Alexandrescu's book" http://erdani.com/index.php/books/modern-c-design/

Thanks to updates to the language, some of the hackery in there is no longer nearly so devilish, and there the language standard provides idioms that are simpler but "good enough if not better" for most people (tuples, smart pointers, move semantics, etc.), so a lot of the specific designs in the book _are_ starting to become passé. Still, it is a fantastic book for understanding the expressive power of C++'s multiparadigm design.