From: Matthias Maier <tamiko@43-1.org>
Date: Thu, 28 Feb 2019 20:23:12 +0000 (-0600)
Subject: SparsityPattern::Iterator  - add a constructor for initalizing an iterator from an... 
X-Git-Tag: v9.1.0-rc1~313^2~1
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2b541384f0210bbf8140d7442ede9039fee4a831;p=dealii.git

SparsityPattern::Iterator  - add a constructor for initalizing an iterator from an accessor

When trying to increment a sparsity pattern iterator:

  auto iterator = sparsity_pattern.begin();
  iterator++;

The corresponding function in LinearIndexIterator:

  template <class DerivedIterator, class AccessorType>
  inline DerivedIterator
  LinearIndexIterator<DerivedIterator, AccessorType>::operator++(int)
  {
    const DerivedIterator copy(this->accessor);
    operator+=(1);
    return copy;
  }

creates a copy that is initialized by the accessor. Thus, we need a
constructor that can create an interator from an accessor.
---

diff --git a/include/deal.II/lac/sparsity_pattern.h b/include/deal.II/lac/sparsity_pattern.h
index 89c507a31e..573c6c2947 100644
--- a/include/deal.II/lac/sparsity_pattern.h
+++ b/include/deal.II/lac/sparsity_pattern.h
@@ -298,6 +298,12 @@ namespace SparsityPatternIterators
      * the zeroth row).
      */
     Iterator(const SparsityPattern *sp, const std::size_t linear_index);
+
+    /**
+     * Constructor. Create an iterator into the sparsity pattern @p sp for
+     * a given accessor.
+     */
+    Iterator(const Accessor &accessor);
   };
 } // namespace SparsityPatternIterators
 
@@ -1272,6 +1278,13 @@ namespace SparsityPatternIterators
                             const std::size_t      linear_index)
     : LinearIndexIterator<Iterator, Accessor>(Accessor(sp, linear_index))
   {}
+
+
+  inline Iterator::Iterator(const Accessor &accessor)
+    : LinearIndexIterator<Iterator, Accessor>(accessor)
+  {}
+
+
 } // namespace SparsityPatternIterators