Using Bit-wise operators with an Enum and an unsigned char - Results in 0

Question

The RentCar function isn't working properly, I want it to compare binary 1's and 0's to switch the default 0 value of the first bit to a value of 1 but it seems to output

0 0 0

When it should be outputting

0 1 0

It seems to work fine if I set variables such as

unsigned char Car0 = 1;

etc, but it doesn't seem to like Enums...

#include <iostream>
using namespace std;

enum CARS { Car0 = 1, Car1 = 2, Car2 = 4, Car3 = 8, Car4 = 16, Car5 = 32, Car6 = 64, Car7 = 128 };


void RentCar(unsigned char f, CARS c) {
    f = f | c;
}

void ReturnCar(unsigned char f, CARS c) {
    f = f ^ c;
}

bool RentalStatus(unsigned char f, CARS c) {
    if ((f & c) == c) {
        return true;
    }
    else {
        return false;
    }
}

//void showFleet() {
//  int car = 0;
//  while (car < 8) {
//      cout << "Car" << car << ": ";
//      if (fleet & car) {
//
//      }
//  }
//}

int main() {

    unsigned char fleet = 0; // 1 byte, 1 bit per car status 

    cout << (int) fleet << endl;

    RentCar(fleet, Car0);

    cout << (int) fleet << endl;

    cout << RentalStatus(fleet, Car0);

}

I'm presuming that this question is about "pass by value" vs "pass by reference" — Drew Dormann, Oct 27 '21 at 00:46
`unsigned char f` is not the same variable as `unsigned char fleet`. You are changing `f` and then expecting `fleet` to have changed. — Drew Dormann, Oct 27 '21 at 00:52
Oh my goodness, I cannot believe how I forgot about &f! I feel so stupid now haha — JEKBURRI, Oct 27 '21 at 01:05
Thank you guys so much! I've been staring at this for hours... — JEKBURRI, Oct 27 '21 at 01:05
@JEKBURRI consider learning to use a debugger. If you had stepped through this code in a debugger, you would have saved hours of your time on this problem alone. — Drew Dormann, Oct 27 '21 at 01:12

Using Bit-wise operators with an Enum and an unsigned char - Results in 0

0 Answers0