Classify Lvalues and Rvalues

1#include <iostream>
2 
3int main() {
4    {
5        int x = 5;
6        int result = x;
7        std::cout << "x: " << result << ", x is now " << x << "\n";
8    }
9    {
10        int x = 5;
11        int result = 10;
12        std::cout << "10: " << result << ", x is now " << x << "\n";
13    }
14    {
15        int x = 5;
16        int result = x + 2;
17        std::cout << "x + 2: " << result << ", x is now " << x << "\n";
18    }
19    {
20        int x = 5;
21        int result = (x += 2);
22        std::cout << "x += 2: " << result << ", x is now " << x << "\n";
23    }
24    {
25        int x = 5;
26        int result = ++x;
27        std::cout << "++x: " << result << ", x is now " << x << "\n";
28    }
29    {
30        int x = 5;
31        int result = x++;
32        std::cout << "x++: " << result << ", x is now " << x << "\n";
33    }
34    return 0;
35}