void attachArguments(std::vector<MathData> const & args, size_t arity, int optionals);
///
MacroData const * macro() { return macro_; }
void attachArguments(std::vector<MathData> const & args, size_t arity, int optionals);
///
MacroData const * macro() { return macro_; }
/// optional argument attached? (only in DISPLAY_NORMAL mode)
size_t optionals_;
/// fold mode to be set in next metrics call?
/// optional argument attached? (only in DISPLAY_NORMAL mode)
size_t optionals_;
/// fold mode to be set in next metrics call?