Perform a lexicographic three-way comparison of the specified lhs and the specified rhs multisets by using the comparison operators of KEY on each element; return the result of that comparison.
Declared in <bslstl_multiset.h>
template<
class KEY,
class COMPARATOR,
class ALLOCATOR>
BloombergLP::bslalg::SynthThreeWayUtil::Result<KEY>
operator<=>(
multiset<KEY, COMPARATOR, ALLOCATOR> const& lhs,
multiset<KEY, COMPARATOR, ALLOCATOR> const& rhs);