From 56bb8618700200f2051f68bb787afdfda0bd8621 Mon Sep 17 00:00:00 2001
From: Daniel Arndt <arndtd@ornl.gov>
Date: Mon, 2 Mar 2020 14:55:24 -0500
Subject: [PATCH] Use a template for Utilities::reverse_permutation and
 Utilities::invert_permutation

---
 include/deal.II/base/utilities.h | 65 +++++++++++++++++++---------
 source/base/utilities.cc         | 72 --------------------------------
 2 files changed, 45 insertions(+), 92 deletions(-)

diff --git a/include/deal.II/base/utilities.h b/include/deal.II/base/utilities.h
index 096f93dcab..887576437c 100644
--- a/include/deal.II/base/utilities.h
+++ b/include/deal.II/base/utilities.h
@@ -562,32 +562,18 @@ namespace Utilities
    * $p_i\in [0,N)$ and $p_i\neq p_j$ for $i\neq j$), produce the reverse
    * permutation $q_i=N-1-p_i$.
    */
-  std::vector<unsigned int>
-  reverse_permutation(const std::vector<unsigned int> &permutation);
+  template <typename Integer>
+  std::vector<Integer>
+  reverse_permutation(const std::vector<Integer> &permutation);
 
   /**
    * Given a permutation vector (i.e. a vector $p_0\ldots p_{N-1}$ where each
    * $p_i\in [0,N)$ and $p_i\neq p_j$ for $i\neq j$), produce the inverse
    * permutation $q_0\ldots q_{N-1}$ so that $q_{p_i}=p_{q_i}=i$.
    */
-  std::vector<unsigned int>
-  invert_permutation(const std::vector<unsigned int> &permutation);
-
-  /**
-   * Given a permutation vector (i.e. a vector $p_0\ldots p_{N-1}$ where each
-   * $p_i\in [0,N)$ and $p_i\neq p_j$ for $i\neq j$), produce the reverse
-   * permutation $q_i=N-1-p_i$.
-   */
-  std::vector<std::uint64_t>
-  reverse_permutation(const std::vector<std::uint64_t> &permutation);
-
-  /**
-   * Given a permutation vector (i.e. a vector $p_0\ldots p_{N-1}$ where each
-   * $p_i\in [0,N)$ and $p_i\neq p_j$ for $i\neq j$), produce the inverse
-   * permutation $q_0\ldots q_{N-1}$ so that $q_{p_i}=p_{q_i}=i$.
-   */
-  std::vector<std::uint64_t>
-  invert_permutation(const std::vector<std::uint64_t> &permutation);
+  template <typename Integer>
+  std::vector<Integer>
+  invert_permutation(const std::vector<Integer> &permutation);
 
   /**
    * Given an arbitrary object of type T, use boost::serialization utilities
@@ -1442,6 +1428,45 @@ namespace Utilities
                  allow_compression);
   }
 
+
+
+  template <typename Integer>
+  std::vector<Integer>
+  reverse_permutation(const std::vector<Integer> &permutation)
+  {
+    const std::size_t n = permutation.size();
+
+    std::vector<Integer> out(n);
+    for (std::size_t i = 0; i < n; ++i)
+      out[i] = n - 1 - permutation[i];
+
+    return out;
+  }
+
+
+
+  template <typename Integer>
+  std::vector<Integer>
+  invert_permutation(const std::vector<Integer> &permutation)
+  {
+    const std::size_t n = permutation.size();
+
+    std::vector<Integer> out(n, numbers::invalid_unsigned_int);
+
+    for (std::size_t i = 0; i < n; ++i)
+      {
+        AssertIndexRange(permutation[i], n);
+        out[permutation[i]] = i;
+      }
+
+    // check that we have actually reached
+    // all indices
+    for (unsigned int i = 0; i < n; ++i)
+      Assert(out[i] != numbers::invalid_unsigned_int,
+             ExcMessage("The given input permutation had duplicate entries!"));
+
+    return out;
+  }
 } // namespace Utilities
 
 
diff --git a/source/base/utilities.cc b/source/base/utilities.cc
index 3db17cab85..7f918ad5e4 100644
--- a/source/base/utilities.cc
+++ b/source/base/utilities.cc
@@ -868,78 +868,6 @@ namespace Utilities
 
 
 
-  template <typename Integer>
-  std::vector<Integer>
-  reverse_permutation(const std::vector<Integer> &permutation)
-  {
-    const std::size_t n = permutation.size();
-
-    std::vector<Integer> out(n);
-    for (std::size_t i = 0; i < n; ++i)
-      out[i] = n - 1 - permutation[i];
-
-    return out;
-  }
-
-
-
-  template <typename Integer>
-  std::vector<Integer>
-  invert_permutation(const std::vector<Integer> &permutation)
-  {
-    const std::size_t n = permutation.size();
-
-    std::vector<Integer> out(n, numbers::invalid_unsigned_int);
-
-    for (std::size_t i = 0; i < n; ++i)
-      {
-        AssertIndexRange(permutation[i], n);
-        out[permutation[i]] = i;
-      }
-
-    // check that we have actually reached
-    // all indices
-    for (unsigned int i = 0; i < n; ++i)
-      Assert(out[i] != numbers::invalid_unsigned_int,
-             ExcMessage("The given input permutation had duplicate entries!"));
-
-    return out;
-  }
-
-
-
-  std::vector<unsigned int>
-  reverse_permutation(const std::vector<unsigned int> &permutation)
-  {
-    return reverse_permutation<unsigned int>(permutation);
-  }
-
-
-
-  std::vector<unsigned int>
-  invert_permutation(const std::vector<unsigned int> &permutation)
-  {
-    return invert_permutation<unsigned int>(permutation);
-  }
-
-
-
-  std::vector<std::uint64_t>
-  reverse_permutation(const std::vector<std::uint64_t> &permutation)
-  {
-    return reverse_permutation<std::uint64_t>(permutation);
-  }
-
-
-
-  std::vector<std::uint64_t>
-  invert_permutation(const std::vector<std::uint64_t> &permutation)
-  {
-    return invert_permutation<std::uint64_t>(permutation);
-  }
-
-
-
   namespace System
   {
 #if defined(__linux__)
-- 
2.39.5