ng-class one time binding - angularjs

Question

I'm wondering if it's possible to have a ng-class with class one time binded and class which are evaluated each digest cycle.
<div ng-class="{'one_time_binded_class': isMonkey(), 'not_one_time_binded_class': isUnicorn()}"></div>
I know I can one time bind the complete ng-class with ng-class="::{...}"
but my need is to one time bind a particular expression
Of course, this thing doesn't work :
<div ng-class="{'my_static_class': ::isMonkey(), 'my_dynamic_class': isUnicorn()}"></div>
Is there a way to do it ?

Answer 1

Method 1:
class="some-class {{::expression ? 'my-class' : ''}}"
Method 2:
ng-class="::{'my-class': expression}"

Answer 2

One way I can think of doing this (if I followed what you were trying to say) is as follows...
.blue{
color: blue;
}
.underline{
text-decoration: underline;
}
.lineThrough{
text-decoration: line-through;
}
<div ng-app ng-controller="myCtrl">
<p ng-class="{'blue': isMonkey()}" class="{{isUnicorn() ? dynamicClass: ''}}">My Text</p>
<button ng-click="monkey = !monkey">Monkey</button>
<button ng-click="unicorn = !unicorn">Unicorn</button>
<button ng-click="toggleClass()">Toggle</button>
</div>
function myCtrl($scope) {
$scope.dynamicClass = "underline";
$scope.monkey = true;
$scope.unicorn = true;
$scope.isMonkey = function () {
return $scope.monkey;
}
$scope.isUnicorn = function () {
return $scope.unicorn;
}
$scope.toggleClass = function(){
$scope.dynamicClass = $scope.dynamicClass === "underline"? "lineThrough": "underline";
}
}
JSFiddle

Answer 3

An important part of one time binding is that it not be bound until the 'expression' is not undefined. The best answer so far, by #ifadey, his Method 1 evaluates to an empty string when 'expression' is undefined, which get's bound. This is contrary to the expected feature behavior. Method 2 is equally unhelpful in this late binding scenario.
Do do this correctly, directly answering op's question:
class="some-class {{::expression ? 'one-time-class' : undefined}}"
ng-class="{ 'my-dynamic-class' : expression2 }"
or the more technically correct but ugly:
class="some-class {{::expression ? 'one-time-class' : (expression===undefined ? undefined : '')}}"