I have an 

`ng-if="dc.emailNotificationSchedule.progressInterval === dc.SkillCompletionProgressIntervals.NEVER_LOGGED_IN"`. 

What i want to do is to have one time bindings for both variables in `ng-if`. But when i try to use 

`ng-if="(::dc.emailNotificationSchedule.progressInterval) === (::dc.SkillCompletionProgressIntervals.NEVER_LOGGED_IN)"` 

angular throws the following error : 

> 
> Error: [$parse:syntax] Syntax Error: Token ':' not a primary
>  expression at column 2 of the expression
>  [(::dc.emailNotificationSchedule.progressInterval) ===
>  (::dc.SkillCompletionProgressIntervals.NEVER\_LOGGED\_IN)] starting at  
> 
>  [::dc.emailNotificationSchedule.progressInterval) ===  
> 
>  (::dc.SkillCompletionProgressIntervals.NEVER\_LOGGED\_IN)].
> 
> 
> 

What is the right way ?