C++11 / Genrated constructor

I have been working on a C++ project started by someone else (who left the company). He has written a piece of code which seems to work pretty well but I cannot understand it.

Here is below a simplified version of the code:

There are two classes :

class Algo_t {
protected :
    Matrix_t m_Matrix ;
public:
    Algo_t(Matrix_t && Matrix) {
        DoSomething();
    }
};

class Matrix_t {
protected :
    std::ifstream & m_iftsream ;
public:
    Matrix_t(std::ifstream && ifstream) {
        DoSomething();
    }
};

In the main:

There is the following call in the main function:

char * pMyFileName = agrv[1] ;
Algo_t MyAlgo(ifstream(pMyFileName));

First I was very surprised that the code compiled without any error because there is no constructor of Algo_t taking ifstream as a parameter. I was more surprised to notice that this code works very well.

Are the constructor generated by the compiler or there is some new feature introduced by C++11 (with the rvalue...)?