These functions inspect the properties and contents of
struct missing_values objects.
The first set of functions inspects the discrete values that 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_values would return nonzero for
Returns the discrete user-missing value in mv with the given
index. The caller must not modify or free the returned value or
refer to it after modifying or freeing mv. The index must be
less than the number of discrete user-missing values in mv, as
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.
Stores the low endpoint of mv’s range in
the high endpoint of the range in
*high. mv must
include a range.