C++Primer Fifth Edition: Exercise 2.15 2.16 2.17

Exercise 2.15
(b) The reference must be an object and cannot be a literal value
(d) The reference must be initialized and bound to the object

Exercise 2.16
(a) Assign the value of d bound to r2 to 3.14159
(b) Assign a reference of type
double to a value of type int (c) Assign a value of type double to int type, data will be lost
(d) Reference of double type will Value is assigned to int type, data will be lost

Exercise 2.17

#include<iostream>

int main()
{
    
    
    int i, & ri = i;
    i = 5;
    ri = 10;

    std::cout << i << " " << ri << std::endl;
}

10 10