https://www.coldfix.eu/2015/05/16/bison-c++11/
https://www.geeksforgeeks.org/flex-fast-lexical-analyzer-generator/
http://anoopsarkar.github.io/compilers-class/yacc-practice.html
vid calculator written with flex/bison
https://nullprogram.com/blog/2019/01/25/
books
courses
http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2017/p0707r0.pdf
A Clang-based prototype is available at github.com/asutton/clang (source) and cppx.godbolt.org (live compiler).
https://ghjang.github.io/computer%20programming/2017/08/10/building_prototype_clang_for_metaclass.html