angularjs - Disabling checkbox with one way binding -

i have 1 checkbox list. need disable elements have model value set false initially. because of 2 way binding have problem when deselect 1 checkbox becomes disabled. how solve it?

<div class="item-s" ng-repeat="element in model.elements">     <input id="element{{$index.tostring()}}"         type="checkbox"         ng-true-value="true"         ng-false-value="false"         ng-model="element.value"         ng-disabled="!element.value" />     <label for="element{{$index.tostring()}}">{{element.name}}</label> </div> 

adding :: in front of binding expression causes evaluated once. should need:

ng-disabled="::!element.value" 

here's angular's docs on one-time binding.