Added two preprocessor macros: UNUSED and UNUSED_FUNCTION

Author: robertodr

CHANGELOG.md

@@ -22,6 +22,8 @@
   The hook will check the license headers, amend them where possible and abort
   where not possible, showing the commands needed to update the license.
   _NOT recommended_ The hook can be skipped by passing the `--no-verify` option to `git commit`
+- An `UNUSED` preprocessor macro to mark arguments as unused.
+- An `UNUSED_FUNCTION` preprocessor macro to mark functions as unused.
 
 ### Changed
 

include/Config.hpp.in

@@ -41,6 +41,19 @@
 #define attribute(x)
 #endif
 
+#ifdef __GNUC__
+#  define UNUSED(x) UNUSED_ ## x __attribute__((__unused__))
+#else
+#  define UNUSED(x) UNUSED_ ## x
+#endif
+
+#ifdef __GNUC__
+#  define UNUSED_FUNCTION(x) __attribute__((__unused__)) UNUSED_ ## x
+#else
+#  define UNUSED_FUNCTION(x) UNUSED_ ## x
+#endif
+
+
 #include <boost/current_function.hpp>
 
 // Inspired from Eigen EIGEN_DEFAULT_DENSE_INDEX_TYPE