MacOS attempt

Author: Thalhammer

.github/workflows/compiler-support.yml

@@ -3,7 +3,7 @@ name: Compiler Compatibility CI
 on:
   push:
     branches: [master]
-  #pull_request:
+  pull_request:
 
 jobs:
   build:

src/io_engine_generic_unix.cpp

@@ -1,6 +1,10 @@
 #ifndef _WIN32
 #include "io_engine_generic_unix.h"
 
+#ifdef __APPLE__
+#define _DARWIN_C_SOURCE
+#endif
+
 #include <cstring>
 
 #include <fcntl.h>