Re: [Suggestion] A syntactic sugar for cast.

[Ward]

Cast is not only for value conversion. When deal with inheritance relationship 
of object, it usually need to cast an object to it's subclass. For example:
    
    
    if obj of Child:
      let child = cast[Child](obj)
    
    Run

In this case, I think use obj[Child] is more clear. However, this is just my 
opinion, any one can decide use it or not.