[已解决]为什么这段代码编译不通过

iloveass

我将SB2成员函数设为Building类的友元，为啥还是访问不了Building类里的私有方法

#include <iostream>
#include <string>
using namespace std;

class Building
{
        //告诉编译器  goodGay类中的visit成员函数 是Building好朋友，可以访问私有内容
public:
        Building();

public:
        string m_SittingRoom; //客厅
private:
        string m_BedRoom;//卧室
    friend void a(Building& b);
    friend class SB1;
    friend void SB2::visit();
};

Building::Building()
{
        this->m_SittingRoom = "客厅";
        this->m_BedRoom = "卧室";
}

void a(Building& b){
    cout << b.m_SittingRoom << endl;
    cout << b.m_BedRoom << endl;
}

class SB1{
public:
    SB1(){
        sb = new Building();
    }

    void visit(){
        cout << sb->m_SittingRoom << endl;
        cout << sb->m_BedRoom << endl;
    }

    Building* sb;
};

class SB2{
public:
    SB2(){
        sb = new Building();
    }

    void visit(){
        cout << sb->m_SittingRoom << endl;
        cout << sb->m_BedRoom << endl;
    }

    Building* sb;
};

int main(){
}

最佳答案

月排行榜 / 总排行榜

jhq999

2023-2-14 19:20:25

#include <iostream>
#include <string>
using namespace std;
class Building;
class SB2{//////////////
public:
    Building *sb;
    SB2();
    void visit();
};
class Building
{
        //告诉编译器  goodGay类中的visit成员函数 是Building好朋友，可以访问私有内容
public:
        Building();

public:
        string m_SittingRoom; //客厅
private:
        string m_BedRoom;//卧室
    friend void a(Building& b);
    friend class SB1;
    friend void SB2::visit();
};

Building::Building()
{
        this->m_SittingRoom = "客厅";
        this->m_BedRoom = "卧室";
}

void a(Building& b){
    cout << b.m_SittingRoom << endl;
    cout << b.m_BedRoom << endl;
}
SB2::SB2(){
        sb = new Building();
    }
void SB2::visit(){
        cout << sb->m_SittingRoom << endl;
        cout << sb->m_BedRoom << endl;
    }
class SB1{
public:
    SB1(){
        sb = new Building();
    }

    void visit(){
        cout << sb->m_SittingRoom << endl;
        cout << sb->m_BedRoom << endl;
    }

    Building* sb;
};






int main(){
    SB2 s2;
    s2.visit();
}

跳转到最佳答案楼层

iloveass

私有成员变量 不是私有方法

iloveass

求助啊

iloveass

有人吗

dolly_yos2

编译不通过编译器说什么了？说的是什么意思？

jhq999

friend void SB2::visit();//sb2声明在后，Building不认识

iloveass

jhq999 发表于 2023-2-14 18:24

是不是在第5行之前加个class SB2;

要是的话，还是错的

error: invalid use of incomplete type ‘class SB2’

jhq999

#include <iostream>
#include <string>
using namespace std;
class Building;
class SB2{//////////////
public:
    Building *sb;
    SB2();
    void visit();
};
class Building
{
        //告诉编译器  goodGay类中的visit成员函数 是Building好朋友，可以访问私有内容
public:
        Building();

public:
        string m_SittingRoom; //客厅
private:
        string m_BedRoom;//卧室
    friend void a(Building& b);
    friend class SB1;
    friend void SB2::visit();
};

Building::Building()
{
        this->m_SittingRoom = "客厅";
        this->m_BedRoom = "卧室";
}

void a(Building& b){
    cout << b.m_SittingRoom << endl;
    cout << b.m_BedRoom << endl;
}
SB2::SB2(){
        sb = new Building();
    }
void SB2::visit(){
        cout << sb->m_SittingRoom << endl;
        cout << sb->m_BedRoom << endl;
    }
class SB1{
public:
    SB1(){
        sb = new Building();
    }

    void visit(){
        cout << sb->m_SittingRoom << endl;
        cout << sb->m_BedRoom << endl;
    }

    Building* sb;
};






int main(){
    SB2 s2;
    s2.visit();
}