diff --git a/libcxx/test/std/iterators/iterator.container/ssize.sfinae.compile.pass.cpp b/libcxx/test/std/iterators/iterator.container/ssize.sfinae.compile.pass.cpp
new file mode 100644
--- /dev/null
+++ b/libcxx/test/std/iterators/iterator.container/ssize.sfinae.compile.pass.cpp
@@ -0,0 +1,31 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+// UNSUPPORTED: libcpp-has-no-concepts
+
+// <iterator>
+
+// template <class T, ptrdiff_t N>
+//   constexpr ptrdiff_t ssize(const T (&array)[N]) noexcept;
+//
+// Peter Dimov gives "clang -m32" as an example of a platform where the
+// use of ptrdiff_t, not size_t, has an observable SFINAE effect.
+
+#include <iterator>
+#include <climits>
+
+static_assert(!(sizeof(std::ptrdiff_t) == 4 && sizeof(std::size_t) == 8), "Run only on these platforms");
+
+template<class T>
+concept HasSsize = requires (T&& t) {
+    std::ssize(t);
+};
+
+//static_assert( HasSsize<char[size_t(INT_MAX) + 0]>);
+//static_assert(!HasSsize<char[size_t(INT_MAX) + 1]>);