cpp报错：C-struct error-Field has incomplete type

Posted 2022-07-11 Harris-H

cpp报错：C-struct error-Field has incomplete type

程序定义如下代码：

struct Node

　　Node son;
;

The error means that you try and add a member to the struct of a type that isn’t fully defined yet, so the compiler cannot know its size in order to determine the objects layout.

In you particular case, you try and have struct Cat hold a complete object of itself as a member (the mother field). That sort of infinite recursion in type definition is of course impossible.

Nevertheless, structures can contain pointers to other instances of themselves.

这是stackoverflow上的一段解释，就是说这样用会造成无限递归

The recursion is in the type containing itself completely as a member.而这个递归就是在一个type中完全以它为类型作为一个成员。

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但是可以用指针来代替

struct Node
	Node * son;
;

Why struct Cat *children member does not make the type recursive? 指针类型为什么不会造成循环

because it’s a pointer. You don’t need the complete type definition to declare a pointer to it.指针不需要一个完整的类定义来声明