Macro id_in_queue 

macro_rules! id_in_queue {
    ( $id:ident, $head:ident, $tail:ident ) => { ... };
}

Macro of an expression to know if an id is still contain by the queue that have a circular buffer

The buffer have two pointer that indicate head and tail. Every ID in this range is considered for the queue.

In the following example:

• o represent active items
• - represent inactive items

If the head is before the tail:

[      |start      |end  ]
[------oooooooooooo------]

If the head is after the tail:

[      |end        |start]
[oooooo------------oooooo]