fd::to_iso_weekday_value — Visitor for iso_weekday_variant and functor yielding a iso_weekday_value.
// In header: <fd/date_time_typed.h> struct to_iso_weekday_value { // public member functions constexpr iso_weekday_value operator()(iso_weekday) const; iso_weekday_value operator()(special_iso_weekday) const; constexpr iso_weekday_value operator()(iso_weekday_value) const; constexpr iso_weekday_value operator()(int) const; };