Select Driver Overload

Question

Problem: Select Driver Overload. Solve this hands-on electronics task on EWskills.

Accepted Answer

#include 
using namespace std;

void init(int pin) {
    cout << "PIN " << pin;
}

void init(int* portPtr) {
    cout << "PORT NULL";
}

int main() {
    int mode;
    cin >> mode;

    if (mode == 1) {
        int pin;
        cin >> pin;
        init(pin);        // calls int overload
    }
    else if (mode == 2) {
        init(nullptr);    // calls pointer overload
    }

    return 0;
}

Explanation & Logic Summary:

Two overloads exist: one takes int, one takes int*
Using 0 or NULL can select the wrong overload
nullptr enforces pointer overload selection
Output confirms which overload was executed

Firmware Relevance & Real-World Context:

HAL APIs often overload based on:
- pin vs port
- index vs pointer
- buffer vs size
Passing 0 can silently:
- select pin 0 unintentionally
- bypass pointer-based initialization
nullptr eliminates these ambiguity-driven bugs

38. Select Driver Overload