bool mv_is_num_missing (const struct missing_values *, double, enum mv_class);
bool mv_is_str_missing (const struct missing_values *, const uint8_t[],
enum mv_class);
bool mv_is_num_missing (const struct missing_values *, double, enum mv_class);
bool mv_is_str_missing (const struct missing_values *, const uint8_t[],
enum mv_class);