From: Sebastian Proell <sebastian.proell@tum.de>
Date: Mon, 6 Mar 2023 15:52:26 +0000 (+0100)
Subject: make_array_view overload for AlignedVector
X-Git-Tag: v9.5.0-rc1~506^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F14846%2Fhead;p=dealii.git

make_array_view overload for AlignedVector
---

diff --git a/doc/news/changes/minor/20230306Proell b/doc/news/changes/minor/20230306Proell
new file mode 100644
index 0000000000..ce0a5abb3b
--- /dev/null
+++ b/doc/news/changes/minor/20230306Proell
@@ -0,0 +1,3 @@
+New: Provide overloads for `make_array_view` for `AlignedVector`.
+<br>
+(Sebastian Proell, 2023/03/06)
diff --git a/include/deal.II/base/array_view.h b/include/deal.II/base/array_view.h
index 31a5435823..05057a30c9 100644
--- a/include/deal.II/base/array_view.h
+++ b/include/deal.II/base/array_view.h
@@ -30,6 +30,9 @@
 DEAL_II_NAMESPACE_OPEN
 
 // Forward declaration
+template <class T>
+class AlignedVector;
+
 template <int N, typename T>
 class Table;
 
@@ -1062,6 +1065,74 @@ make_array_view(const std::vector<ElementType> &vector,
 
 
 
+/**
+ * Create a writable view to an entire AlignedVector object. See the
+ * documentation of the corresponding overload for std::vector for more
+ * information.
+ */
+template <typename ElementType>
+inline ArrayView<ElementType>
+make_array_view(AlignedVector<ElementType> &vector)
+{
+  return ArrayView<ElementType>(vector.data(), vector.size());
+}
+
+
+
+/**
+ * Create a read-only view to an entire AlignedVector object. See the
+ * documentation of the corresponding overload for std::vector for more
+ * information.
+ */
+template <typename ElementType>
+inline ArrayView<const ElementType>
+make_array_view(const AlignedVector<ElementType> &vector)
+{
+  return ArrayView<const ElementType>(vector.data(), vector.size());
+}
+
+
+
+/**
+ * Create a writable view to a part of an AlignedVector object. See the
+ * documentation of the corresponding overload for std::vector for more
+ * information.
+ */
+template <typename ElementType>
+inline ArrayView<ElementType>
+make_array_view(AlignedVector<ElementType> &vector,
+                const std::size_t           starting_index,
+                const std::size_t           size_of_view)
+{
+  Assert(starting_index + size_of_view <= vector.size(),
+         ExcMessage("The starting index and size of the view you want to "
+                    "create would lead to a view that extends beyond the end "
+                    "of the given vector."));
+  return ArrayView<ElementType>(&vector[starting_index], size_of_view);
+}
+
+
+
+/**
+ * Create a read-only view to a part of an AlignedVector object. See the
+ * documentation of the corresponding overload for std::vector for more
+ * information.
+ */
+template <typename ElementType>
+inline ArrayView<const ElementType>
+make_array_view(const AlignedVector<ElementType> &vector,
+                const std::size_t                 starting_index,
+                const std::size_t                 size_of_view)
+{
+  Assert(starting_index + size_of_view <= vector.size(),
+         ExcMessage("The starting index and size of the view you want to "
+                    "create would lead to a view that extends beyond the end "
+                    "of the given vector."));
+  return ArrayView<const ElementType>(&vector[starting_index], size_of_view);
+}
+
+
+
 /**
  * Create a view to an entire std::array object. This is equivalent to
  * initializing an ArrayView object with a pointer to the first element and
diff --git a/tests/base/array_view_19.cc b/tests/base/array_view_19.cc
new file mode 100644
index 0000000000..d8a115cc94
--- /dev/null
+++ b/tests/base/array_view_19.cc
@@ -0,0 +1,83 @@
+// ---------------------------------------------------------------------
+//
+// Copyright (C) 2015 - 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 for class ArrayView with AlignedVector, using make_array_view
+
+#include <deal.II/base/aligned_vector.h>
+#include <deal.II/base/array_view.h>
+
+#include "../tests.h"
+
+
+void
+test()
+{
+  AlignedVector<int> v(10, 1.0);
+
+  {
+    ArrayView<int> a(&v[4], 3); // writable view
+    a[2] = 42;
+
+    Assert(a[2] == 42, ExcInternalError());
+    Assert(v[6] == 42, ExcInternalError());
+  }
+
+  {
+    ArrayView<int> a = make_array_view(v); // writable view
+    a[1]             = 43;
+
+    Assert(v[1] == 43, ExcInternalError());
+    Assert(a[6] == 42, ExcInternalError());
+  }
+
+  {
+    ArrayView<const int> a2(&v[4], 3); // readable view
+    Assert(a2[2] == 42, ExcInternalError());
+  }
+
+  {
+    ArrayView<const int> a2 = make_array_view(v); // readable view
+    Assert(a2[1] == 43, ExcInternalError());
+    Assert(a2[6] == 42, ExcInternalError());
+  }
+
+  {
+    // writable view on subrange
+    ArrayView<int> a2 = make_array_view(v, 1, 7);
+    a2[0]             = 44;
+    Assert(a2[0] == 44, ExcInternalError());
+    Assert(a2[5] == 42, ExcInternalError());
+  }
+
+  {
+    // readable view on subrange
+    ArrayView<const int> a2 = make_array_view(v, 1, 7);
+    Assert(a2[0] == 44, ExcInternalError());
+    Assert(a2[5] == 42, ExcInternalError());
+  }
+
+  deallog << "OK" << std::endl;
+}
+
+
+
+int
+main()
+{
+  initlog();
+
+  test();
+}
diff --git a/tests/base/array_view_19.output b/tests/base/array_view_19.output
new file mode 100644
index 0000000000..0fd8fc12f0
--- /dev/null
+++ b/tests/base/array_view_19.output
@@ -0,0 +1,2 @@
+
+DEAL::OK