Cardinality of a multirange? How many ranges or gaps are there in a multirange?

How do I obtain the cardinality of a multirange? I'm using range_agg() to aggregate ranges, which merges ranges if they are continuous, or returns what looks like an array of ranges if the ranges are discontinuous. I want to detect if there are any gaps in the multirange and wanted to use cardinality() for this. A cardinality of 1 would mean no gaps, a cardinality of 2 means 1 gap, etc. However cardinality is not defined on a multirange, because a multirange is not technically an array: with x(a) as ( values (daterange(date '2024-01-30', date '2024-03-31', '[)')), (daterange(date '2024-04-01', date '2024-04-30', '[)')) ) select cardinality(range_agg(a)) from x; returns ERROR: function cardinality(datemultirange) does not exist LINE 6: select cardinality(range_agg(a)) from x; I can probably implement the function myself with unnest() and counting the number of resulting rows, but I'm curious if there are any other good solutions.