Rvalue and Lvalue Links

Question

I have a printInt function as shown below.

void printInt(const int& a)
{
    cout<<a<<endl;
}

When I call a function using the following arguments, for example

int a=5;
printInt(a);
printInt(5);

It works great. But when I change the definition of a function to

void printInt(int& a)
{
    cout<<a<<endl;
}

This gives an error to call printInt(5). Now my question is why const int&is both an lvalue reference and an rvalue, whereas it int&is only an lvalue reference. As far as I know, int&&is an rvalue reference. So, how can one refer to an rvalue link?

To summarize my problem:

• Lvalue control parameter

  void printInt(int& a)
  {
      cout<<a<<endl;
  }
  

• Rvalue control parameter

  void printInt(int&& a)
  {
      cout<<a<<endl;
  }    
  

• Both lvalue and rvalue. but how?

  void printInt(const int& a)
  {
      cout<<a<<endl;
  }
  

Answer 1

const int& lvalue. , , rvalues. int& lvalue, . , - .