A look at Dart's null safety syntax

[ElegantBeef]

I don't know what the first point means, but to the second it's not a postfix 
but the following works. 
    
    
    import std/options
    template `?`(a: typedesc): typedesc = Option[a]
    converter toOpt[T](t: T): ?T = some(t)
    var abc: ?string
    
    if abc.isNone:
      abc = "test"
    assert abc.get == "test"
    
    
    Run