[topaxi]

The xxBy methods are just for convenience, usually you can provide your own function for each method.

Example:

    Ember.computed.map('myArray', function() {
      return foo.bar;
    })

vs.

    Ember.computed.mapBy('myArray', 'bar')

What you are asking for, would need a change to Ember.computed.uniq, allowing it to accept a custom function.