D6079 introduced a function that switches over an enum class parameter
and returns a std::string, which raises a warning from the compiler that
"control reaches end of non-void function". since this should never
happen, an assert(false) after the switch silences that warning.
to really bulletproof it though, defaultless switch statements over an enum
value that do not have a specific case for each should raise an error and not a warning
edit: also promoted -Wreturn-type to an error, h/t @deadalnix