Return a format list which contains the intersection of the formats of
a and b. Also, all the references of a, all the references of b, and
a and b themselves will be deallocated.
If a and b do not share any common formats, neither is modified, and NULL
is returned.
Return a format list which contains the intersection of the formats of a and b. Also, all the references of a, all the references of b, and a and b themselves will be deallocated.
If a and b do not share any common formats, neither is modified, and NULL is returned.