These functions inspect the properties and contents of
struct missing_values objects.
The first set of functions inspects the discrete values that numeric and short string sets of user-missing values may contain:
Returns true if mv contains no user-missing values, false if it contains at least one user-missing value (either a discrete value or a numeric range).
Returns the width of the user-missing values that mv represents.
Returns the number of discrete user-missing values included in mv. The return value will be between 0 and 3. For sets of numeric user-missing values that include a range, the return value will be 0 or 1.
Returns true if mv has at least one discrete user-missing values, that is, if
mv_n_valueswould return nonzero for mv.
Copies the discrete user-missing value in mv with the given index into value. The index must be less than the number of discrete user-missing values in mv, as reported by
The second set of functions inspects the single range of values that numeric sets of user-missing values may contain:
Returns true if mv includes a range, false otherwise.