This forward declares the typedef identifier and the struct tag at the same time. Just put such forward declarations of all your struct before the real declarations. As long as you only use pointers to these struct inside the declarations everything should be fine, then. nitpick: names with ...
I get the following error: 'ports' uses undefined struct 'port_t' I thought as I have declared the struct in my .h file and having the actual structure in the .c file was ok. I need to have the forward declaration as I want to hide some data in my port.c file. In my port.h...
在定义A时B还没有定义,则要引用B就需要前向声明结构B(struct B;)。示例如下: typedef BOOL (*func)(const DefStruct *ptStrt); typedef struct DefStruct_t{ int i; func f; }DefStruct; 如上在DefStruct中使用回调函数func声明,这样交叉引用必然编译报错。进行前向声明即可: typedef struct DefStruct_t ...
Another question, how does forward declaration really work? Say I have these two structs and a function pointer. This wont compile as is. How can I fix this ? // File ObjectA.h typedef struct { ObjectB b; } ObjectA; // File ObjectB.h typedef struct { func f; } ObjectB; int (...
C中的前向聲明 (Forward Declaration in C) I wanted to ask about Forward Declarations in C. How generally they work. For example if in a file I declare struct task_struct; and define the struct in other file will it work? Because as far as I know Compiler must know the size of variab...
1 struct __list { 2 struct __list *prev; 3 struct __list *next; 4 viud *data; 5 }; 1. 2. 3. 4. 5. 在list.h中这样: 1 typedef struct __list *list_t; 1. 这样的话,链表结构的具体定义对用户来说就是透明的了,不能直接的访问结构成员,只能提供相应的接口来供访问,这样做的好处显...
typedef TBL_SET_MODE (*OperTypeFunc)(INT8U *pTblEntry);typedef INT8U (*CmpRecFunc)(VOID *pvCmpData, VOID *pvRecData); //为避免头文件交叉引用,与CompareRecFunc异名同构//表属性信息typedef struct{ INT16U wMaxEntryNum; //表属性最大表项数目(实体记录数目wMaxRecNum * wMaxEntryNum <= MAX...
编译器警告你一个向前声明的struct lol。C允许您执行以下操作: struct lol; /* forward declaration, the size and members of struct lol are unknown */ 这在定义自引用结构时最常用,但是在定义从未在头文件中定义的私有结构时也很有用。由于存在后者,因此可以声明接收或返回指向不完整结构的指针的函数: void ...
另一种解决方案是将前向声明和 typedef 放入单独的标头中,并包括: // ForwardDeclarations.h #pragma once namespace Foo { struct Bar; typedef Bar Baz; } // SomeFile.h #include "ForwardDeclarations.h" Foo::Baz baz; 当然,这实际上并没有减少要包含的文件数量,编译器仍然必须从磁盘读取这个文件,但...
6)头文件内不允许定义变量和函数,只能有宏、类型(typedef/struct/union/enum等)及变量和函数的声明。特殊情况下可extern基本类型的全局变量,源文件通过包含该头文件访问全局变量。但头文件内不应extern自定义类型(如结构体)的全局变量,否则将迫使本不需要访问该变量的源文件包含自定义类型所在头文件[1]。