Trace decltype With Arithmetic

1#include <iostream>
2 
3int main() {
4    decltype(10) a = 10;
5    decltype(10L) b = 10L;
6    decltype(10U) c = 10U;
7    decltype(5 / 2) d = 5 / 2;
8    decltype(5 / 2.0) e = 5 / 2.0;
9    std::cout << a << "\n";
10    std::cout << b << "\n";
11    std::cout << c << "\n";
12    std::cout << d << "\n";
13    std::cout << e << "\n";
14    std::cout << d + e << "\n";
15    std::cout << d * 2 << "\n";
16    return 0;
17}