Question

Consider the following code:

class B;

class A
{
  public:
    A() {}
    A(B &b);
};

class B {};

A::A(B &b) {}

int main()
{
    B b;

    const A &refa = b;// does this line create a temporary value?

    return 0;
}

My question is: does the code const A &refa = b; create a temporary value or not?

Answer 1

Yes, a temporary object A(b) is created in the intialization statement, and it is immediately bound to the constant-reference refa. This has the effect of prolonging the lifetime of the temporary to match the scope of the refa variable.