Many user defined datatypes created in "classical" C++ allow many states which should not happen in production.
This playground has the goal to show some of them and how to avoid them using C++14/17 standard library type additions.
The build environment is:
This playground was written for a C++ Usergroup session (https://cpp-ug-luzern.blogspot.com/). It may not yet be ready to use without further context.