Add macro M_IF_FUNCOBJ to handle conditional expression if the function object is defined

m-core.h

@@ -1263,6 +1263,15 @@ extern void m_no_default_function(void)   __attribute__((error("The requested op
 #define M_NDEBUG_TEST               0
 #define M_IF_DEBUG(a)               M_IF(M_TEST_NDEBUG_P())(,a)
 
+
+/* If the Function Object is included, expands the code,
+   otherwise do nothing.
+   M_FUNCOBJ_IS_NOT_DEFINED is defined to 0.
+   NOTE: M_IF is the variable is not defined assummes yes.
+*/
+#define M_IF_FUNCOBJ(a)             M_IF(M_FUNCOBJ_IS_NOT_DEFINED)( ,a)
+
+
 /* Helper macro to redefine a function with a default value :
    If there is only one variable as the __VA_ARGS__, print
    __VA_ARGS__ then ', value', instead only __VA_ARGS__.

m-funcobj.h

@@ -23,7 +23,7 @@
  * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 #ifndef MSTARLIB_FUNCOBJ_H
-#define MSTARLIB_FUNCOBJ_H 1
+#define MSTARLIB_FUNCOBJ_H
 
 #include "m-core.h"
 
@@ -70,6 +70,9 @@
 /********************************** INTERNAL ************************************/
 /********************************************************************************/
 
+/* To be used by M_IF_FUNCOBJ macro */
+#define M_FUNCOBJ_IS_NOT_DEFINED 0
+
 /* Design Constraints:
  *  callback SHALL be the first member of the structures in all the definitions.
  *