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