tan-wei

// https://stackoverflow.com/questions/54786278/how-do-i-write-a-maintainable-fast-compile-time-bit-mask-in-c
#include <bitset>

enum Flags { A = 1, B = 2, C = 3, D = 5,
             E = 8, F = 13, G = 21, H,
             I, J, K, L, M, N, O };

#define CPP_VERSION 14

#if CPP_VERSION==11