varivar=[:]ivar.className//__NSDictionaryIvari=1i.className//error:'Int'doesnothaveamembernamed'className'

If you want to get the type of a primitive, you have to usebridgeToObjectiveC(). Example:

var i = 1

i.bridgeToObjectiveC().className // __NSCFNumber

println("\(object_getClassName(now))");