1 files changed, 94 insertions, 0 deletions
diff --git a/libgomp/testsuite/libgomp.c++/target-flex-41.C b/libgomp/testsuite/libgomp.c++/target-flex-41.C
new file mode 100644
index 0000000..4d36341
--- /dev/null
+++ b/libgomp/testsuite/libgomp.c++/target-flex-41.C
@@ -0,0 +1,94 @@
+/* { dg-additional-options "-std=c++20" } */
+
+/* <iterator> c++20  */
+
+/* std::common_iterator uses std::variant.  */
+
+#include <vector>
+#include <iterator>
+#include <span>
+
+//TODO PR120454 "C++ constexpr vs. OpenMP implicit mapping"
+#pragma omp declare target(std::ranges::distance, std::ranges::next)
+
+#include "target-flex-common.h"
+
+namespace stdr = std::ranges;
+
+template<typename It0, typename It1>
+bool simple_equal(const It0 begin0, const It0 end0,
+		  const It1 begin1, const It1 end1) BL_NOEXCEPT
+{
+  It0 it0 = begin0;
+  It1 it1 = begin1;
+  for (; it0 != end0; ++it0, ++it1)
+    if (it1 == end1 || *it0 != *it1)
+      return false;
+  return true;
+}
+
+template<typename It, typename OutIt>
+void simple_copy(const It begin, const It end, OutIt out) BL_NOEXCEPT
+{
+  for (It it = begin; it != end; ++it, ++out)
+    *out = *it;
+}
+
+template<typename T, std::size_t Size>
+bool test(const T (&arr)[Size])
+{
+  bool ok;
+  T out_rev_arr[Size];
+  T out_fwd_arr[Size];
+  T out_first_half_arr[Size / 2];
+  #pragma omp target defaultmap(none) \
+		     map(from: ok, out_rev_arr[:Size], out_fwd_arr[:Size], \
+			       out_first_half_arr[:Size / 2]) \
+		     map(to: arr[:Size])
+    {
+      bool inner_ok = true;
+      {
+	std::span<const T> span = {arr, Size};
+	std::vector<T> rev_vec(std::reverse_iterator{span.end()},
+			       std::reverse_iterator{span.begin()});
+	VERIFY (std::distance(span.begin(), span.end())
+		== std::distance(rev_vec.begin(), rev_vec.end()));
+	VERIFY (stdr::distance(span.begin(), span.end())
+		== stdr::distance(rev_vec.begin(), rev_vec.end()));
+	VERIFY (stdr::distance(span) == stdr::distance(rev_vec));
+	VERIFY (simple_equal(span.begin(), span.end(),
+			     std::reverse_iterator{rev_vec.end()},
+			     std::reverse_iterator{rev_vec.begin()}));
+	simple_copy(rev_vec.begin(), rev_vec.end(), out_rev_arr);
+	simple_copy(std::reverse_iterator{rev_vec.end()},
+		    std::reverse_iterator{rev_vec.begin()},
+		    out_fwd_arr);
+	using counted_iter = std::counted_iterator<decltype(span.begin())>;
+	using common_iter = std::common_iterator<counted_iter,
+						 std::default_sentinel_t>;
+	std::vector<T> front_half;
+	simple_copy(common_iter{counted_iter{span.begin(), Size / 2}},
+		    common_iter{std::default_sentinel},
+		    std::back_insert_iterator{front_half});
+	VERIFY (simple_equal(span.begin(), stdr::next(span.begin(), Size / 2),
+			     front_half.begin(), front_half.end()));
+	simple_copy(front_half.begin(), front_half.end(), out_first_half_arr);
+      }
+      end:
+      ok = inner_ok;
+    }
+  VERIFY_NON_TARGET (simple_equal(std::reverse_iterator{arr + Size},
+				  std::reverse_iterator{arr},
+				  out_rev_arr, out_rev_arr + Size));
+  VERIFY_NON_TARGET (simple_equal(arr, arr + Size,
+				  out_fwd_arr, out_fwd_arr + Size));
+  VERIFY_NON_TARGET (simple_equal(arr, arr + Size / 2,
+				  out_first_half_arr, out_first_half_arr + Size / 2));
+  return ok;
+}
+
+int main()
+{
+  int arr[] = {0, 1, 2, 3, 4, 5, 6, 7};
+  return test(arr) ? 0 : 1;
+}