From: Wolfgang Bangerth <bangerth@colostate.edu>
Date: Fri, 27 Aug 2021 20:26:21 +0000 (-0600)
Subject: Use std::prev in one place.
X-Git-Tag: v9.4.0-rc1~1007^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F12717%2Fhead;p=dealii.git

Use std::prev in one place.
---

diff --git a/include/deal.II/lac/block_indices.h b/include/deal.II/lac/block_indices.h
index 1c1315b4e2..3689b3c3e7 100644
--- a/include/deal.II/lac/block_indices.h
+++ b/include/deal.II/lac/block_indices.h
@@ -25,6 +25,7 @@
 #include <deal.II/base/utilities.h>
 
 #include <cstddef>
+#include <iterator>
 #include <vector>
 
 DEAL_II_NAMESPACE_OPEN
@@ -331,9 +332,8 @@ BlockIndices::global_to_local(const size_type i) const
   Assert(n_blocks > 0, ExcLowerRangeType<size_type>(i, size_type(1)));
 
   // start_indices[0] == 0 so we might as well start from the next one
-  const auto it = --std::upper_bound(std::next(start_indices.begin()),
-                                     start_indices.end(),
-                                     i);
+  const auto it = std::prev(
+    std::upper_bound(std::next(start_indices.begin()), start_indices.end(), i));
 
   return {std::distance(start_indices.begin(), it), i - *it};
 }