[libcxx][ranges] implement `std::ranges::set_difference`
implement `std::ranges::set_difference`
reused classic std::set_difference
added unit tests
Differential Revision: https://reviews.llvm.org/D128983
NOKEYCHECK=True
GitOrigin-RevId: 1cdec6c96e852f4ebac61711a622535bcaf07542
diff --git a/include/algorithm b/include/algorithm
index a7236a3..fef1ad3 100644
--- a/include/algorithm
+++ b/include/algorithm
@@ -530,6 +530,24 @@
requires permutable<iterator_t<R>>
constexpr borrowed_subrange_t<R>
ranges::remove_if(R&& r, Pred pred, Proj proj = {}); // since C++20
+
+ template<class I, class O>
+ using set_difference_result = in_out_result<I, O>; // since C++20
+
+ template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
+ weakly_incrementable O, class Comp = ranges::less,
+ class Proj1 = identity, class Proj2 = identity>
+ requires mergeable<I1, I2, O, Comp, Proj1, Proj2>
+ constexpr set_difference_result<I1, O>
+ set_difference(I1 first1, S1 last1, I2 first2, S2 last2, O result,
+ Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {}); // since C++20
+
+ template<input_range R1, input_range R2, weakly_incrementable O,
+ class Comp = ranges::less, class Proj1 = identity, class Proj2 = identity>
+ requires mergeable<iterator_t<R1>, iterator_t<R2>, O, Comp, Proj1, Proj2>
+ constexpr set_difference_result<borrowed_iterator_t<R1>, O>
+ set_difference(R1&& r1, R2&& r2, O result,
+ Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {}); // since C++20
}
@@ -1300,6 +1318,7 @@
#include <__algorithm/ranges_replace.h>
#include <__algorithm/ranges_replace_if.h>
#include <__algorithm/ranges_reverse.h>
+#include <__algorithm/ranges_set_difference.h>
#include <__algorithm/ranges_sort.h>
#include <__algorithm/ranges_stable_sort.h>
#include <__algorithm/ranges_swap_ranges.h>