Occasionally, a member function is logically const, but it still needs to change the value of a member. To a user, the function appears not to change the state of its object. However, some detail that the user cannot directly observe is updated. This is often called logical constness.
The storage specifier mutable specifies that a member should be stored in a way that allows updating – even when it is a member of a const object.
By definition, a struct is a class in which members are by default public.
A member function defined within the class definition – rather than simply declared there – is taken to be an inline member function.
本文章为转载内容，我们尊重原作者对文章享有的著作权。如有内容错误或侵权问题，欢迎原作者联系我们进行内容更正或删除文章。
