--- /dev/null
+++ xnu/xnu-7195.141.2/tests/safe_allocation_src/operator.subscript.cpp
@@ -0,0 +1,84 @@
+//
+// Tests for
+//  T& operator[](std::ptrdiff_t n);
+//  T const& operator[](std::ptrdiff_t n) const;
+//
+
+#include <libkern/c++/safe_allocation.h>
+#include <darwintest.h>
+#include "test_utils.h"
+#include <cstddef>
+#include <limits>
+
+struct T {
+	long i;
+};
+
+template <typename RawT, typename QualT>
+static void
+tests()
+{
+	// Test the non-const version
+	{
+		RawT* memory = reinterpret_cast<RawT*>(malloc_allocator::allocate(10 * sizeof(RawT)));
+		for (RawT* ptr = memory; ptr != memory + 10; ++ptr) {
+			*ptr = RawT{ptr - memory}; // number from 0 to 9
+		}
+
+		test_safe_allocation<QualT> array(memory, 10, libkern::adopt_memory);
+		for (std::ptrdiff_t n = 0; n != 10; ++n) {
+			QualT& element = array[n];
+			CHECK(&element == memory + n);
+		}
+	}
+
+	// Test the const version
+	{
+		RawT* memory = reinterpret_cast<RawT*>(malloc_allocator::allocate(10 * sizeof(RawT)));
+		for (RawT* ptr = memory; ptr != memory + 10; ++ptr) {
+			*ptr = RawT{ptr - memory}; // number from 0 to 9
+		}
+
+		test_safe_allocation<QualT> const array(memory, 10, libkern::adopt_memory);
+		for (std::ptrdiff_t n = 0; n != 10; ++n) {
+			QualT const& element = array[n];
+			CHECK(&element == memory + n);
+		}
+	}
+
+	// Test with OOB offsets (should trap)
+	{
+		using Alloc = libkern::safe_allocation<RawT, malloc_allocator, tracking_trapping_policy>;
+		RawT* memory = reinterpret_cast<RawT*>(malloc_allocator::allocate(10 * sizeof(RawT)));
+		Alloc const array(memory, 10, libkern::adopt_memory);
+
+		// Negative offsets
+		{
+			tracking_trapping_policy::reset();
+			(void)array[-1];
+			CHECK(tracking_trapping_policy::did_trap);
+		}
+		{
+			tracking_trapping_policy::reset();
+			(void)array[-10];
+			CHECK(tracking_trapping_policy::did_trap);
+		}
+
+		// Too large offsets
+		{
+			tracking_trapping_policy::reset();
+			(void)array[10];
+			CHECK(tracking_trapping_policy::did_trap);
+		}
+		{
+			tracking_trapping_policy::reset();
+			(void)array[11];
+			CHECK(tracking_trapping_policy::did_trap);
+		}
+	}
+}
+
+T_DECL(operator_subscript, "safe_allocation.operator.subscript") {
+	tests<T, T>();
+	tests<T, T const>();
+}