[libc++] Implement ranges::starts_with

1 files changed, 13 insertions, 0 deletions

diff --git a/libcxx/include/algorithm b/libcxx/include/algorithm
index 18a89eb1a4dc..280333e5b33d 100644
--- a/libcxx/include/algorithm
+++ b/libcxx/include/algorithm
@@ -446,6 +446,18 @@ namespace ranges {
            indirect_unary_predicate<projected<iterator_t<R>, Proj>> Pred>
     constexpr bool ranges::none_of(R&& r, Pred pred, Proj proj = {});                       // since C++20
 
+  template<input_iterator I1, sentinel_for<I1> S1, input_iterator I2, sentinel_for<I2> S2,
+          class Pred = ranges::equal_to, class Proj1 = identity, class Proj2 = identity>
+    requires indirectly_comparable<I1, I2, Pred, Proj1, Proj2>
+    constexpr bool ranges::starts_with(I1 first1, S1 last1, I2 first2, S2 last2, Pred pred = {},
+                                      Proj1 proj1 = {}, Proj2 proj2 = {});                 // since C++23
+
+  template<input_range R1, input_range R2, class Pred = ranges::equal_to, class Proj1 = identity,
+          class Proj2 = identity>
+    requires indirectly_comparable<iterator_t<R1>, iterator_t<R2>, Pred, Proj1, Proj2>
+    constexpr bool ranges::starts_with(R1&& r1, R2&& r2, Pred pred = {},
+                                      Proj1 proj1 = {}, Proj2 proj2 = {});                // since C++23
+
   template<input_iterator I1, sentinel_for<I1> S1,
           random_access_iterator I2, sentinel_for<I2> S2,
           class Comp = ranges::less, class Proj1 = identity, class Proj2 = identity>
@@ -1874,6 +1886,7 @@ template <class BidirectionalIterator, class Compare>
 #include <__algorithm/ranges_sort_heap.h>
 #include <__algorithm/ranges_stable_partition.h>
 #include <__algorithm/ranges_stable_sort.h>
+#include <__algorithm/ranges_starts_with.h>
 #include <__algorithm/ranges_swap_ranges.h>
 #include <__algorithm/ranges_transform.h>
 #include <__algorithm/ranges_unique.h>