From: Peter Munch <peterrmuench@gmail.com>
Date: Wed, 18 Mar 2020 00:17:09 +0000 (+0100)
Subject: VectorizedArrayIterator enable std::distance and add operator+
X-Git-Tag: v9.2.0-rc1~410^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7c4216e81470308863ca7138baec54933a40552a;p=dealii.git

VectorizedArrayIterator enable std::distance and add operator+
---

diff --git a/include/deal.II/base/vectorization.h b/include/deal.II/base/vectorization.h
index d5f4b30d51..3ff22504fa 100644
--- a/include/deal.II/base/vectorization.h
+++ b/include/deal.II/base/vectorization.h
@@ -169,6 +169,25 @@ public:
     return *this;
   }
 
+  /**
+   * Create new iterator, which is shifted by @p offset.
+   */
+  VectorizedArrayIterator<T>
+  operator+(const unsigned int &offset) const
+  {
+    return VectorizedArrayIterator<T>(*data, lane + offset);
+  }
+
+  /**
+   * Compute distance between this iterator and iterator @p other.
+   */
+  unsigned int
+  operator-(const VectorizedArrayIterator<T> &other) const
+  {
+    AssertIndexRange(other.lane, lane + 1);
+    return lane - other.lane;
+  }
+
 private:
   /**
    * Pointer to the actual VectorizedArray.
@@ -5439,6 +5458,19 @@ namespace std
     return x.get_min(y);
   }
 
+
+
+  /**
+   * Iterator traits for VectorizedArrayIterator.
+   */
+  template <class T>
+  struct iterator_traits<dealii::VectorizedArrayIterator<T>>
+  {
+    using iterator_category = random_access_iterator_tag;
+    using value_type        = typename T::value_type;
+    using difference_type   = unsigned int;
+  };
+
 } // namespace std
 
 #endif
diff --git a/tests/base/vectorization_iterator_02.cc b/tests/base/vectorization_iterator_02.cc
index c0ed5367a3..5f69531500 100644
--- a/tests/base/vectorization_iterator_02.cc
+++ b/tests/base/vectorization_iterator_02.cc
@@ -14,7 +14,7 @@
 // ---------------------------------------------------------------------
 
 
-// test for std::max_element on VectorizedArray
+// test for std::max_element and std::distance on VectorizedArray
 
 #include <deal.II/base/vectorization.h>
 
@@ -27,6 +27,14 @@ test_const(const VectorizedArray<Number> &vector)
 {
   AssertDimension(*std::max_element(vector.begin(), vector.end()),
                   VectorizedArray<Number>::n_array_elements - 1);
+  AssertDimension(std::distance(vector.begin(),
+                                std::max_element(vector.begin(), vector.end())),
+                  VectorizedArray<Number>::n_array_elements - 1);
+  AssertDimension(std::distance(vector.begin(),
+                                vector.begin() +
+                                  (VectorizedArray<Number>::n_array_elements -
+                                   1)),
+                  VectorizedArray<Number>::n_array_elements - 1);
 }
 
 template <typename Number>
@@ -35,6 +43,14 @@ test_nonconst(VectorizedArray<Number> &vector)
 {
   AssertDimension(*std::max_element(vector.begin(), vector.end()),
                   VectorizedArray<Number>::n_array_elements - 1);
+  AssertDimension(std::distance(vector.begin(),
+                                std::max_element(vector.begin(), vector.end())),
+                  VectorizedArray<Number>::n_array_elements - 1);
+  AssertDimension(std::distance(vector.begin(),
+                                vector.begin() +
+                                  (VectorizedArray<Number>::n_array_elements -
+                                   1)),
+                  VectorizedArray<Number>::n_array_elements - 1);
 }
 
 template <typename Number>