avoid name clashes with c++ keywords

include/margo.h

@@ -84,10 +84,10 @@ hg_return_t margo_bulk_transfer(
 
 /**
  * Retrive the Margo instance that has been associated with a Mercury class
- * @param [in] class Mercury class
+ * @param [in] cl Mercury class
  * @returns Margo instance on success, NULL on error
  */
-margo_instance_id margo_hg_class_to_instance(hg_class_t *class);
+margo_instance_id margo_hg_class_to_instance(hg_class_t *cl);
 
 /**
  * macro that defines a function to glue an RPC handler to a fiber

src/margo.c

@@ -214,13 +214,13 @@ hg_return_t margo_bulk_transfer(
     return(hret);
 }
 
-margo_instance_id margo_hg_class_to_instance(hg_class_t *class)
+margo_instance_id margo_hg_class_to_instance(hg_class_t *cl)
 {
     int i;
 
     for(i=0; i<handler_mapping_table_size; i++)
     {
-        if(handler_mapping_table[i].class == class)
+        if(handler_mapping_table[i].class == cl)
             return(handler_mapping_table[i].mid);
     }
     return(NULL);