From c6d1d73c1e9b1ae48d448f5229c224ea43c87046 Mon Sep 17 00:00:00 2001
From: Matthias Maier <tamiko@43-1.org>
Date: Fri, 19 Feb 2021 19:13:44 -0600
Subject: [PATCH] add a test

---
 tests/base/ndarray.cc     | 54 +++++++++++++++++++++++++++++++++++++++
 tests/base/ndarray.output |  1 +
 2 files changed, 55 insertions(+)
 create mode 100644 tests/base/ndarray.cc
 create mode 100644 tests/base/ndarray.output

diff --git a/tests/base/ndarray.cc b/tests/base/ndarray.cc
new file mode 100644
index 0000000000..be4d074c66
--- /dev/null
+++ b/tests/base/ndarray.cc
@@ -0,0 +1,54 @@
+// ---------------------------------------------------------------------
+//
+// Copyright (C) 2021 by the deal.II authors
+//
+// This file is part of the deal.II library.
+//
+// The deal.II library is free software; you can use it, redistribute
+// it, and/or modify it under the terms of the GNU Lesser General
+// Public License as published by the Free Software Foundation; either
+// version 2.1 of the License, or (at your option) any later version.
+// The full text of the license can be found in the file LICENSE.md at
+// the top level directory of deal.II.
+//
+// ---------------------------------------------------------------------
+
+
+// test that the ndarray type alias does what it promises to do.
+
+#include <deal.II/base/ndarray.h>
+
+#include <type_traits>
+
+#include "../tests.h"
+
+int
+main()
+{
+  initlog();
+
+  dealii::ndarray<double>             r0;
+  dealii::ndarray<double, 1>          r1;
+  dealii::ndarray<double, 1, 2>       r2;
+  dealii::ndarray<double, 1, 2, 3>    r3;
+  dealii::ndarray<double, 1, 2, 3, 4> r4;
+
+  static_assert(std::is_same<decltype(r0), double>::value,
+                "types must be the same");
+  static_assert(std::is_same<decltype(r1), std::array<double, 1>>::value,
+                "types must be the same");
+  static_assert(
+    std::is_same<decltype(r2), std::array<std::array<double, 2>, 1>>::value,
+    "types must be the same");
+  static_assert(
+    std::is_same<decltype(r3),
+                 std::array<std::array<std::array<double, 3>, 2>, 1>>::value,
+    "types must be the same");
+  static_assert(
+    std::is_same<decltype(r4),
+                 std::array<std::array<std::array<std::array<double, 4>, 3>, 2>,
+                            1>>::value,
+    "types must be the same");
+
+  return 0;
+}
diff --git a/tests/base/ndarray.output b/tests/base/ndarray.output
new file mode 100644
index 0000000000..8b13789179
--- /dev/null
+++ b/tests/base/ndarray.output
@@ -0,0 +1 @@
+
-- 
2.39.5