C ++: RVO (Return Value optimization)

# Include <stdio. h>

Class RVO

{

Public:

RVO ()

{

Printf ("I am in constructor % d \ n", this );

}

RVO (const RVO & c_rvo)

{

Printf ("I am in copy constructor % d \ n", this );

}

~ RVO ()

{

Printf ("I am in destructor % d \ n", this );

}

RVO & operator = (const RVO & RHs)

{

Printf ("I am in operator % d = % d \ n", this, & RHs );

Return * this;

}

Int mem_var;

};

RVO mymethod (int I)

{

Printf ("3 \ n ");

RVO; // I am in constructor 1244896

Printf ("4 \ n ");

RVO. mem_var = I;

Printf ("5 \ n ");

Return (RVO); // 1244948cc ,~ 1244896

Printf ("6 \ n ");

}

Int main ()

{

Printf ("1 \ n ");

RVO; // I am in constructor 1245016

Printf ("2 \ n ");

RVO = mymethod (5); // I am in copy constructor

Printf ("7 \ n ");

Return 0 ;//~ 1245016

}

RVO mymethod (RVO & hddenobj, int I)

{

Printf ("3 \ n ");

RVO;
RVO. RVO (); // I am in constructor 1244896

Printf ("4 \ n ");

RVO. mem_var = I;

Printf ("5 \ n ");

Hddenobj. RVO (RVO); // I am in copy constructor
RVO .~ RVO ();

Return; // 1244948cc ,~ 1244896

Printf ("6 \ n ");

}

Int main ()

{

Printf ("1 \ n ");

RVO; // I am in constructor 1245016

Printf ("2 \ n ");

RVO = mymethod (5); // I am in copy constructor

Printf ("7 \ n ");

Return 0 ;//~ 1245016

}

1
I am in constructor 1245016
2
3
I am in constructor 1244888
4
5
I am in copy constructor 1244944
I am in destructor 1244888
I am in operator 1245016 = 1244944
I am in destructor 1244944
7
I am in destructor 1245016