--- /dev/null
+++ xnu/xnu-10063.121.3/tests/bounded_array_ref_src/ctor.begin_end.cpp
@@ -0,0 +1,80 @@
+//
+// Tests for
+//  explicit bounded_array_ref(T* first, T* last);
+//
+
+#include <libkern/c++/bounded_array_ref.h>
+#include "test_policy.h"
+#include <darwintest.h>
+#include <darwintest_utils.h>
+
+struct T { int i; };
+inline bool
+operator==(T const& a, T const& b)
+{
+	return a.i == b.i;
+};
+
+template <typename T>
+static void
+tests()
+{
+	T array[5] = {T{0}, T{1}, T{2}, T{3}, T{4}};
+
+	// T{0}     T{1}     T{2}     T{3}     T{4}     <one-past-last>
+	//   ^                                                ^
+	//   |                                                |
+	// first                                             last
+	{
+		T* first = &array[0];
+		T* last = &array[5];
+		test_bounded_array_ref<T> view(first, last);
+		CHECK(view.data() == &array[0]);
+		CHECK(view.size() == 5);
+		CHECK(view[0] == T{0});
+		CHECK(view[1] == T{1});
+		CHECK(view[2] == T{2});
+		CHECK(view[3] == T{3});
+		CHECK(view[4] == T{4});
+	}
+
+	// T{0}     T{1}     T{2}     T{3}     T{4}     <one-past-last>
+	//   ^        ^
+	//   |        |
+	// first     last
+	{
+		T* first = &array[0];
+		T* last = &array[1];
+		test_bounded_array_ref<T> view(first, last);
+		CHECK(view.data() == &array[0]);
+		CHECK(view.size() == 1);
+		CHECK(view[0] == T{0});
+	}
+
+	// T{0}     T{1}     T{2}     T{3}     T{4}     <one-past-last>
+	//   ^
+	//   |
+	// first,last
+	{
+		T* first = &array[0];
+		T* last = &array[0];
+		test_bounded_array_ref<T> view(first, last);
+		CHECK(view.size() == 0);
+	}
+
+	// T{0}     T{1}     T{2}     T{3}     T{4}     <one-past-last>
+	//                                                    ^
+	//                                                    |
+	//                                               first,last
+	{
+		T* first = &array[5];
+		T* last = &array[5];
+		test_bounded_array_ref<T> view(first, last);
+		CHECK(view.size() == 0);
+	}
+}
+
+T_DECL(ctor_begin_end, "bounded_array_ref.ctor.begin_end") {
+	tests<T>();
+	tests<T const>();
+}