<xstd/bits/bit_algorithm/bit_lexicographical_compare_three_way.hpp>

bit_lexicographical_compare_three_way

As lexicographical_compare_three_way in [alg.three.way], over two ranges rather than two iterator pairs, the shape P2022R3 proposes for ranges::lexicographical_compare_three_way, with:

• Constraints: As for bit_equal.
• Returns: lexicographical_compare_three_way(ranges::begin(r1), ranges::end(r1), ranges::begin(r2), ranges::end(r2)), a strong_ordering. Over two sequences, false precedes true and a prefix precedes the longer sequence. Over two sets it is set's order, the keys compared lexicographically in iteration order: ascending keys position by position, and descending ones as their masks compared as numbers.
• Complexity: As for bit_equal.
• Remarks: lexicographical_compare(r1, r2) is bit_lexicographical_compare_three_way(r1, r2) < 0.