How to pass an argument to Vue.js filters?

Consider:

filters:{
   currency: function(value, arg1){
     return arg1+value;
}

And usage:

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.1/vue.js"></script>
<div id="vue-instance">
  {{123 | currency('$') }}
</div>