All the basic comparisons (<, <=, ==, !=, >=, >) have an associated function object (std::less, std::less_equal, std::equal_to, std::not_equal_to, std::greater_equal, std::greater).
Does the spaceship operator <=> have a similar function object?
If not, why was it not added to the standard library?
std::compare_three_wayis the function object for three-way comparison (aka. spaceship operator).