From f3969daa4a8cea401526cd0ad4813c53e23d10a2 Mon Sep 17 00:00:00 2001
From: Paul Romano <paul.k.romano@gmail.com>
Date: Tue, 18 Apr 2023 22:50:14 -0500
Subject: [PATCH] Ensure compilation with gcc 5 works (refs #2474)

---
 include/openmc/mesh.h     | 4 ++--
 include/openmc/position.h | 8 ++++++--
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/include/openmc/mesh.h b/include/openmc/mesh.h
index 4fdb2eb4ab..cef4e05184 100644
--- a/include/openmc/mesh.h
+++ b/include/openmc/mesh.h
@@ -412,7 +412,7 @@ private:
 
   bool full_phi_ {false};
 
-  constexpr inline int sanitize_angular_index(int idx, bool full, int N) const
+  inline int sanitize_angular_index(int idx, bool full, int N) const
   {
     if ((idx > 0) and (idx <= N)) {
       return idx;
@@ -467,7 +467,7 @@ private:
   bool full_theta_ {false};
   bool full_phi_ {false};
 
-  constexpr inline int sanitize_angular_index(int idx, bool full, int N) const
+  inline int sanitize_angular_index(int idx, bool full, int N) const
   {
     if ((idx > 0) and (idx <= N)) {
       return idx;
diff --git a/include/openmc/position.h b/include/openmc/position.h
index 0200cda3b7..11ea376479 100644
--- a/include/openmc/position.h
+++ b/include/openmc/position.h
@@ -216,14 +216,18 @@ using Direction = Position;
 
 } // namespace openmc
 
+namespace fmt {
+
 template<>
-struct fmt::formatter<openmc::Position> : formatter<std::string> {
+struct formatter<openmc::Position> : formatter<std::string> {
   template<typename FormatContext>
   auto format(const openmc::Position& pos, FormatContext& ctx)
   {
-    return fmt::formatter<std::string>::format(
+    return formatter<std::string>::format(
       fmt::format("({}, {}, {})", pos.x, pos.y, pos.z), ctx);
   }
 };
 
+} // namespace fmt
+
 #endif // OPENMC_POSITION_H