events: Added support for infering event type from Callback objects

While limitations in type inference prevent the event helper from
infering the type of generic function objects, there is nothing
technical preventing inference from the Callback class, where the
function type is encoded in the template parameters.

With adoption of the Callback class as the standard function
representation, it makes sense to support events created from
callback objects.

Author: geky

TESTS/events/queue/main.cpp

@@ -210,7 +210,7 @@ void event_class_helper_test() {
 
 void event_inference_test() {
     counter = 0;
-    EventQueue queue (2048);
+    EventQueue queue(2048);
 
     queue.event(count5, 1, 1, 1, 1, 1).post();
     queue.event(count5, 1, 1, 1, 1).post(1);
@@ -219,9 +219,16 @@ void event_inference_test() {
     queue.event(count5, 1).post(1, 1, 1, 1);
     queue.event(count5).post(1, 1, 1, 1, 1);
 
+    queue.event(callback(count5), 1, 1, 1, 1, 1).post();
+    queue.event(callback(count5), 1, 1, 1, 1).post(1);
+    queue.event(callback(count5), 1, 1, 1).post(1, 1);
+    queue.event(callback(count5), 1, 1).post(1, 1, 1);
+    queue.event(callback(count5), 1).post(1, 1, 1, 1);
+    queue.event(callback(count5)).post(1, 1, 1, 1, 1);
+
     queue.dispatch(0);
 
-    TEST_ASSERT_EQUAL(counter, 30);
+    TEST_ASSERT_EQUAL(counter, 60);
 }