循环 C++ 头文件包括

Circular C++ Header Includes(循环 C++ 头文件包括)

问题描述

在一个项目中，我有 2 个类:

In a project I have 2 classes:

//mainw.h

#include "IFr.h"
...
class mainw
{
public:
static IFr ifr;
static CSize=100;
...
};

//IFr.h

#include "mainw.h"
...
class IFr
{
public float[mainw::CSize];
};

但我无法编译此代码，在 static IFr ifr; 行出现错误.这种交叉包含是否被禁止?

But I cannot compile this code, getting an error at the static IFr ifr; line. Is this kind of cross-inclusion prohibited?

推荐答案

这种交叉包含是否被禁止?

Is this kind of cross-inclusions are prohibited?

是的.

一种变通方法是说 mainw 的 ifr 成员是一个引用或一个指针，这样前向声明就可以了，而不是包含完整的声明，例如:

A work-around would be to say that the ifr member of mainw is a reference or a pointer, so that a forward-declaration will do instead of including the full declaration, like:

//#include "IFr.h" //not this
class IFr; //this instead
...
class mainw
{
public:
static IFr* ifr; //pointer; don't forget to initialize this in mainw.cpp!
static CSize=100;
...
}

或者，在单独的头文件中定义 CSize 值(以便 Ifr.h 可以包含这个其他头文件，而不是包含 mainw.h).

Alternatively, define the CSize value in a separate header file (so that Ifr.h can include this other header file instead of including mainw.h).

这篇关于循环 C++ 头文件包括的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持编程学习网！