Fighting with macOS stdlib

Author: stigrj

examples/CXX_host/example.cpp

@@ -13,6 +13,7 @@
  */
 
 #include <cmath>
+#include <cstdlib>
 #include <iostream>
 
 #include <XCFun/xcfun.h>
@@ -83,7 +84,7 @@ int main(int, char **) {
     std::cout << "The XC energy density is " << res << std::endl;
 
     // compare with reference
-    auto diff = std::fabs(-0.86494159400066051 - res);
+    auto diff = std::abs(-0.86494159400066051 - res);
     if (diff > 1.0e-6)
       std::cout << "derivatives do not match reference numbers" << std::endl;
   }
@@ -114,7 +115,7 @@ int main(int, char **) {
     auto res = derivative(id, vector_length, density);
 
     // compare with reference
-    auto diff = std::fabs(-5.1509916226154067 - res);
+    auto diff = std::abs(-5.1509916226154067 - res);
     if (diff > 1.0e-6)
       std::cout << "derivatives do not match reference numbers" << std::endl;
   }
@@ -148,7 +149,7 @@ int main(int, char **) {
     auto res = derivative(id, vector_length, density);
 
     // compare with reference
-    auto diff = std::fabs(-0.013470456737102541 - res);
+    auto diff = std::abs(-0.013470456737102541 - res);
     if (diff > 1.0e-6)
       std::cout << "derivatives do not match reference numbers" << std::endl;
   }
@@ -186,7 +187,7 @@ int main(int, char **) {
     auto res = derivative(id, vector_length, density);
 
     // compare with reference
-    auto diff = std::fabs(-9.4927931153398468 - res);
+    auto diff = std::abs(-9.4927931153398468 - res);
     if (diff > 1.0e-6)
       std::cout << "derivatives do not match reference numbers" << std::endl;
   }
@@ -240,7 +241,7 @@ int main(int, char **) {
     auto res = derivative(id, vector_length, density);
 
     // compare with reference
-    auto diff = std::fabs(47.091223089835331 - res);
+    auto diff = std::abs(47.091223089835331 - res);
     if (diff > 1.0e-6)
       std::cout << "derivatives do not match reference numbers" << std::endl;
   }