位移枚举

C语言枚举定义

typedef enum
{  

ActionEnumTop   = 1 << 0 ,
//0 0 0 1
//0 0 0 1 =1(往左移动一位)
ActionEnumBottom = 1 << 1 ,
//0 0 0 1
//0 0 1 0 =2(往左移动一位)
ActionEnumLeft   = 1 << 2 ,
ActionEnumRight  = 1 << 3 ,

}ActionEnum;

苹果创建枚举的定义方式

typedef NS_OPTIONS(NSInteger, ActionEnum){
ActionEnumTop   = 1 << 0 ,
ActionEnumBottom = 1 << 1 ,
ActionEnumLeft   = 1 << 2 ,
ActionEnumRight  = 1 << 3 ,

};