C++ 这个和这个区别

下面的程序输出是正确的，但是当我使用这个时出现了一个错误 谁能告诉我这和这意味着什么

#include<iostream>
using namespace std;

class Test 
{
private:
    static int count;
public:
    Test& fun(); // fun() is non-static now
};

int Test::count = 0;

Test& Test::fun() 
{
    Test::count++;
    cout<<Test::count<<" ";
    return *this;
}

int main()  
{
    Test t;
    t.fun().fun().fun().fun();
    return 0;
}

当我用它代替*时，会出现以下错误：

#include<iostream>
using namespace std;

class Test 
{
private:
    static int count;
public:
    Test& fun(); // fun() is non-static now
};

int Test::count = 0;

Test& Test::fun() 
{
    Test::count++;
    cout<<Test::count<<" ";
    return *this;
}

int main()  
{
    Test t;
    t.fun().fun().fun().fun();
    return 0;
}

In member function 'Test& Test::fun()':
invalid initialization of non-const reference of type 'Test&' from an rvalue of type 'Test*'
     return this;

有谁能举个好例子告诉我这个和这个有什么区别吗

#include<iostream>
using namespace std;

class Test 
{
private:
    static int count;
public:
    Test& fun(); // fun() is non-static now
};

int Test::count = 0;

Test& Test::fun() 
{
    Test::count++;
    cout<<Test::count<<" ";
    return *this;
}

int main()  
{
    Test t;
    t.fun().fun().fun().fun();
    return 0;
}

有人能告诉我这是什么意思吗

#include<iostream>
using namespace std;

class Test 
{
private:
    static int count;
public:
    Test& fun(); // fun() is non-static now
};

int Test::count = 0;

Test& Test::fun() 
{
    Test::count++;
    cout<<Test::count<<" ";
    return *this;
}

int main()  
{
    Test t;
    t.fun().fun().fun().fun();
    return 0;
}

此

是指向当前对象的指针

#include<iostream>
using namespace std;

class Test 
{
private:
    static int count;
public:
    Test& fun(); // fun() is non-static now
};

int Test::count = 0;

Test& Test::fun() 
{
    Test::count++;
    cout<<Test::count<<" ";
    return *this;
}

int main()  
{
    Test t;
    t.fun().fun().fun().fun();
    return 0;
}

*此

是当前对象

#include<iostream>
using namespace std;

class Test 
{
private:
    static int count;
public:
    Test& fun(); // fun() is non-static now
};

int Test::count = 0;

Test& Test::fun() 
{
    Test::count++;
    cout<<Test::count<<" ";
    return *this;
}

int main()  
{
    Test t;
    t.fun().fun().fun().fun();
    return 0;
}

您大概知道解引用操作符的作用是什么？我不知道你为什么要任意地把

这个

换成

*这个

。不要这样做。

和的可能重复

#include<iostream>
using namespace std;

class Test 
{
private:
    static int count;
public:
    Test& fun(); // fun() is non-static now
};

int Test::count = 0;

Test& Test::fun() 
{
    Test::count++;
    cout<<Test::count<<" ";
    return *this;
}

int main()  
{
    Test t;
    t.fun().fun().fun().fun();
    return 0;
}