Register Overlay byte and bitfield

#include <iostream>
#include <cstdint>
using namespace std;

union Reg {
    uint8_t raw;
    struct {
        uint8_t en : 1;
        uint8_t mode : 3;
        uint8_t reserved : 4;
    } bits;
};

int main() {
    int val;
    cin >> val;
    Reg r;
    r.raw = static_cast<uint8_t>(val); // Ensure value fits in 8 bits
    cout << "en=" << static_cast<int>(r.bits.en)
         << " mode=" << static_cast<int>(r.bits.mode);
    return 0;
}