From 5ab544f7caee7ecab426bca9bbf57592cdb0ca6a Mon Sep 17 00:00:00 2001
From: Scott R Charlton <charlton@usgs.gov>
Date: Mon, 4 Mar 2024 19:11:28 -0700
Subject: [PATCH] Try this to fix warning on Darwin

---
 src/phreeqcpp/common/Utils.cxx | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/phreeqcpp/common/Utils.cxx b/src/phreeqcpp/common/Utils.cxx
index 44f77b17..6738fa9d 100644
--- a/src/phreeqcpp/common/Utils.cxx
+++ b/src/phreeqcpp/common/Utils.cxx
@@ -17,7 +17,9 @@
 #endif
 
 #if __cplusplus < 201103L // Check if C++ standard is pre-C++11
-#  define nullptr NULL
+#  ifndef nullptr
+#    define nullptr NULL
+#  endif
 #endif
 
 #if defined(PHREEQCI_GUI)