al_peek_next_event - Allegro 5 API

       Copy  the  contents  of  the next event in the event queue specified into ret_event and return true.  The
       original event packet will remain at the head of the queue.  If the event queue is actually  empty,  this
       function returns false and the contents of ret_event are unspecified.

       al_peek_next_event - Allegro 5 API

ALLEGRO_EVENT(3alleg5), al_get_next_event(3alleg5), al_drop_next_event(3alleg5)

Allegro reference manual                                                             al_peek_next_event(3alleg5)

              #include <allegro5/allegro.h>

              bool al_peek_next_event(ALLEGRO_EVENT_QUEUE *queue, ALLEGRO_EVENT *ret_event)