Object
Hash
Symbol
IO
File
Continuation
File::Stat
Data
NilClass
Exception
Array
Proc
String
Numeric
Float
Integer
Bignum
Fixnum
Regexp
Thread
Module
Class
ThreadGroup
Method
UnboundMethod
Struct
Struct::Tms
TrueClass
Time
Dir
Binding
Range
MatchData
FalseClass