struct一般理解應該叫compound value,
佢同int, float一樣, im唔immutable都冇咩關係
至於會唔會慳咗位都係睇language implementation,
好似C++咁struct同class嘅分別就係佢地個名唔同
(仲有一個分別嘅, default public/private囉)
java一開始就標榜OO, 做abstraction,
就算係好簡單嘅compound type, 都要寫做class,
冇其他keyword可以用
有啲language唔用struct呢個字, 但係有細分value同object type,
可能叫data或者其他嘢甚至local用可以anonymous咁define