Also not clear if this is the best way to include it.  Probably need the std::variant approach here too.

I think at 0.4 us/call on this machine

needed a force eval, () needed to be moved

Method from Ulrich Deiters, superancillary from our new paper

added CMakeSettings.json for working with VisualStudio
added missing "template" to dependent template-function calls

Co-authored-by: Tobias Loew <tobi@die-loew.de>