全てのオブジェクトはObjective-Cオブジェク ト >> obj = Object.new => <NSObject: 0x4007e2160> >> obj.methods(true,true) => [:clear_history!, :h!, :history!, .... :"performSelectorOnMainThread:withObject:waitUntilDone:", :"performSelectorOnMainThread:withObject:waitUntilDone:modes:", :"performSelector:onThread:withObject:waitUntilDone:modes:", .... ] Objective-C メソッド 利用可能