Register Bitfields Using Struct Overlay

Code

#include <stdio.h>
#include <stdint.h>

typedef union {
    struct {
        uint8_t enable    : 1;
        uint8_t mode      : 2;
        uint8_t interrupt : 1;
        uint8_t reserved  : 4;
    } bits;
    uint8_t reg;
} ControlRegister;

int main() {
    uint8_t e, m, i;
    scanf("%hhu %hhu %hhu", &e, &m, &i);
    ControlRegister ctrl;
    // Construct and print register value
    /*SOLUTION 1*/
    /*
  
    ctrl.bits.enable = e ;
    ctrl.bits.mode = m;
    ctrl.bits.interrupt = i;*/

    /*SOLUTION 2*/
    ctrl.reg = 0;
    ctrl.reg |= (e << 0) | (m << 1) | (i<<3) ;

    //PRINT SAME FOR SOLUTION 1n2
    printf("%d",ctrl.reg);

    return 0;
}

Solving Approach