From 0baa3f6abb85264c81c98704a2c8b2a07b0f3ec5 Mon Sep 17 00:00:00 2001
From: David Bold <dave@ipp.mpg.de>
Date: Fri, 11 Aug 2023 17:01:51 +0200
Subject: [PATCH 1/2] Add .zpm for sign-independent coding

---
 include/bout/region.hxx | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/include/bout/region.hxx b/include/bout/region.hxx
index 5e2eb9c1a2..0775e6b368 100644
--- a/include/bout/region.hxx
+++ b/include/bout/region.hxx
@@ -308,6 +308,10 @@ struct SpecificInd {
     ASSERT3(dz >= 0);
     return {(ind) % nz < dz ? ind + nz - dz : ind - dz, ny, nz};
   }
+  /// Automatically select zm or zp depending on sign
+  inline SpecificInd zpm(int dz) const {
+    return dz > 0? zp(dz) : zm(-dz);
+  }
 
   // and for 2 cells
   inline SpecificInd xpp() const { return xp(2); }
@@ -319,8 +323,7 @@ struct SpecificInd {
 
   /// Generic offset of \p index in multiple directions simultaneously
   inline SpecificInd offset(int dx, int dy, int dz) const {
-    auto temp = (dz > 0) ? zp(dz) : zm(-dz);
-    return temp.yp(dy).xp(dx);
+    return zpm(dz).yp(dy).xp(dx);
   }
 };
 

From ad06d97d23c9baadb506d870ffe6fa6a54c248fb Mon Sep 17 00:00:00 2001
From: dschwoerer <dschwoerer@users.noreply.github.com>
Date: Tue, 19 Mar 2024 15:39:50 +0000
Subject: [PATCH 2/2] Apply clang-format changes

---
 include/bout/region.hxx | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/include/bout/region.hxx b/include/bout/region.hxx
index 0775e6b368..68810324e3 100644
--- a/include/bout/region.hxx
+++ b/include/bout/region.hxx
@@ -309,9 +309,7 @@ struct SpecificInd {
     return {(ind) % nz < dz ? ind + nz - dz : ind - dz, ny, nz};
   }
   /// Automatically select zm or zp depending on sign
-  inline SpecificInd zpm(int dz) const {
-    return dz > 0? zp(dz) : zm(-dz);
-  }
+  inline SpecificInd zpm(int dz) const { return dz > 0 ? zp(dz) : zm(-dz); }
 
   // and for 2 cells
   inline SpecificInd xpp() const { return xp(2); }