C++没有匹配的"="运算符

Question

class ComplexNum {
public:
    ComplexNum() { }

    ComplexNum& operator= (const ComplexNum&);
    ComplexNum Conjugate();

    ComplexNum& operator= (const ComplexNum& c){
    this->degree = c.degree;
    this->Im = c.Im;
    this->Re = c.Re;
    this->radian = c.radian;
    this->length = c.length;
    return *this;
    }

    ComplexNum Conjugate() {
        ComplexNum Occ = { 0,0,0,0,0 };

    Occ = this;
    }
private:
    double length;
    double Re;
    double Im;
    double degree;
    double radian;
    const double Pi = 3.14159265f;
};

int main(){
    ComplexNum OCC,OCT = {2,4,0,0,0};
    OCC = OCT;
    return 0;
}   
![图片说明](https://img-ask.csdn.net/upload/202009/24/1600950252_998973.png)

Answer 1

ComplexNum Conjugate() {
ComplexNum Occ = { 0,0,0,0,0 };
Occ = *this;
//另外这个函数没有返回值
return Occ;
}