Почему работает присваивание

//Complex.h
#ifndef COMPLEX_H
#define COMPLEX_H
 
#include <iostream>
using std::ostream;
using std::istream;
 
class Complex
{
        friend ostream &operator<<(ostream &, const Complex &);
        
    public:
        Complex (double = 0.0, double = 0.0);
        Complex operator+(const Complex &) const;
        Complex operator-(const Complex &) const;   
        void print() const;
    private:
        double real;
        double imaginary;       
};
#endif

//Complex.cpp
#include <iostream>
using std::cout;
 
#include "Complex.h"
 
Complex::Complex(double realPart, double imaginaryPart) : real(realPart), imaginary(imaginaryPart)
{
}
 
Complex Complex::operator+(const Complex &operand2) const
{
    return Complex(real+operand2.real, imaginary+operand2.imaginary);
}
 
Complex Complex::operator-(const Complex &operand2) const
{
    return Complex(real-operand2.real, imaginary-operand2.imaginary);
}
 
ostream &operator<<(ostream &output, const Complex &s)
{
    output<<'('<<s.real<<((s.imaginary<0) ? " - j" : " + j")<<s.imaginary<<')';
    
    return output;
}

//main.cpp
#include <iostream>
using std::cout;
using std::endl;
using std::boolalpha;
 
#include "Complex.h"
 
int main()
{
    Complex x;
    Complex y(4.3, 8.2);
    Complex z(3.3, -1.1);
    
    x=y+z;                                         //почему это работает???
    cout<<"\n\nx = y + z: "<<endl;
    cout<<x;
    cout<<" = ";
    cout<<y;
    cout<<" + ";
    cout<<z;
    
    return 0;
}

Сomplex(const Complex &pCopy)
{
     real = pCopy.real;
     imaginary = Copy.imaginary;
}

x=Complex(y+z);

class Complex
{
        friend ostream &operator<<(ostream &, const Complex &);
        
    public:
        Complex (double = 0.0, double = 0.0);
        Complex operator+(const Complex &) const;
        Complex operator-(const Complex &) const;   
        void print() const;
    private:
        double real;
        double imaginary;  
        ifstream ifs;//вот что покоробит дефолт     
};