在string :: clear函数的描述中,它说:
clear: Erases the contents of the string,which becomes an empty string (with a length of 0 characters).
在list :: clear函数的描述中,它说:
clear: Removes all elements from the list container (which are destroyed),and leaving the container with a size of 0.
清除是否覆盖字符串和列表的内存或只是释放它们?