My attempt at implementing Queue data structure in Bash

queue.sh

#!/bin/bash

push_queue(){
    element_to_store="$1"
    queue+=($element_to_store)
}
pop_queue(){
    args=${queue[0]}
    queue=("${queue[@]:1}")
}

declare -a queue
echo ${queue[@]} #

push_queue "one"
echo ${queue[@]} # one

push_queue "two"
echo ${queue[@]} # one two 

pop_queue
echo ${queue[@]} # two

push_queue "three"
echo ${queue[@]} # two three

pop_queue
echo ${queue[@]} # three

pop_queue
echo ${queue[@]} #