From 7eb665bdb3faba19f27fdf7349f05e1104520e14 Mon Sep 17 00:00:00 2001
From: Wolfgang Bangerth <bangerth@colostate.edu>
Date: Tue, 24 Oct 2023 11:08:18 -0600
Subject: [PATCH] Make a variable a member variable.

---
 include/deal.II/base/polynomial.h | 7 +++++++
 source/base/polynomial.cc         | 9 +--------
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/include/deal.II/base/polynomial.h b/include/deal.II/base/polynomial.h
index 2f44aa63bc..7adedd9d4d 100644
--- a/include/deal.II/base/polynomial.h
+++ b/include/deal.II/base/polynomial.h
@@ -27,6 +27,7 @@
 #include <array>
 #include <limits>
 #include <memory>
+#include <shared_mutex>
 #include <vector>
 
 DEAL_II_NAMESPACE_OPEN
@@ -572,6 +573,12 @@ namespace Polynomials
      */
     static std::vector<std::unique_ptr<const std::vector<double>>>
       recursive_coefficients;
+
+    /**
+     * The mutex that guards read and write access to the
+     * `recursive_coefficients` array.
+     */
+    static std::shared_mutex coefficients_lock;
   };
 
 
diff --git a/source/base/polynomial.cc b/source/base/polynomial.cc
index 4dba286918..02b4004a5b 100644
--- a/source/base/polynomial.cc
+++ b/source/base/polynomial.cc
@@ -25,7 +25,6 @@
 #include <cmath>
 #include <limits>
 #include <memory>
-#include <shared_mutex>
 
 DEAL_II_NAMESPACE_OPEN
 
@@ -847,18 +846,12 @@ namespace Polynomials
 
   // ------------------ class Hierarchical --------------- //
 
-  // have a lock that guarantees that at most one thread is changing and
-  // accessing the `recursive_coefficients array.
-  namespace
-  {
-    std::shared_mutex coefficients_lock;
-  }
-
   // Reserve space for polynomials up to degree 19. Should be sufficient
   // for the start.
   std::vector<std::unique_ptr<const std::vector<double>>>
     Hierarchical::recursive_coefficients(20);
 
+  std::shared_mutex Hierarchical::coefficients_lock;
 
 
   Hierarchical::Hierarchical(const unsigned int k)
-- 
2.39.5