Object creation process while copying

[xyzt]

Hello
I realized something that I couldn't figure out. Let's say I have a class X and a function,func, which returns a list<X>. When I get the result of func, the copy operator should work I think, but it seems not.here's my code and output:

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

class X
{
	public:
		X()
		{
			cout<<"Default Constructor called\n";
		}
		X(string data):
			_data(data)
	        {
		        cout<<"Constructor called\n";
	        }
		X(const X& x)
		{
			_data = x._data;
		}
		void operator=(const X& x)
		{
			cout<<"Copy operator called\n";
			_data = x._data;
		}

		~X()
		{
			cout<<"Destructor called\n";
		}
		string _data;
	protected:
	private:
};

list<X> func()
{
	list<X> lst;
	X x1("obj name");
	lst.push_back(x1);
	return lst;
}

int main()
{
	list<X> lst = func();
	X x1 = lst.back();
	cout<<x1._data<<"\n";
}

output:
--------------
Constructor called
Destructor called
obj name
Destructor called
Destructor called


Why didn't the copy operator and the default constructor called?
What does it do when it executes this line?:
list<X> lst = func();


Thanks in advance.

[Bazzy]

That line calls the copy constructor ( which is at line 17 in your code )

[xyzt]

Thanks for the quck reply. I got it.
Also I realized that;
X x1 = lst.back();
calls copy constructor, but

X x1;
x1 = lst.back();

calls at first default constructor and then the copy operator.

Thanks again for the reply.