[libc++][ranges] implement `std::ranges::set_intersection`
implement `std::ranges::set_intersection` by reusing the classic `std::set_intersenction`
added unit tests
Differential Revision: https://reviews.llvm.org/D129233
NOKEYCHECK=True
GitOrigin-RevId: 96b674f23cd66e8fee9efde6003dc2032acf58b6
diff --git a/include/algorithm b/include/algorithm
index 785c3ef..0cc4195 100644
--- a/include/algorithm
+++ b/include/algorithm
@@ -604,6 +604,25 @@
set_difference(R1&& r1, R2&& r2, O result,
Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {}); // since C++20
+ template<class I1, class I2, class O>
+ using set_intersection_result = in_in_out_result<I1, I2, 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_intersection_result<I1, I2, O>
+ set_intersection(I1 first1, S1 last1, I2 first2, S2 last2, O result,
+ Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {}); // 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_intersection_result<borrowed_iterator_t<R1>, borrowed_iterator_t<R2>, O>
+ set_intersection(R1&& r1, R2&& r2, O result,
+ Comp comp = {}, Proj1 proj1 = {}, Proj2 proj2 = {}); // since C++20
+
}
constexpr bool // constexpr in C++20
@@ -1378,6 +1397,7 @@
#include <__algorithm/ranges_replace_if.h>
#include <__algorithm/ranges_reverse.h>
#include <__algorithm/ranges_set_difference.h>
+#include <__algorithm/ranges_set_intersection.h>
#include <__algorithm/ranges_sort.h>
#include <__algorithm/ranges_sort_heap.h>
#include <__algorithm/ranges_stable_sort.h>