Overload Resolution Trap

Question

Problem: Overload Resolution Trap. Solve this hands-on electronics task on EWskills.

Accepted Answer

#include 
using namespace std;

void foo(int x) {
    cout << "int overload
";
}

void foo(int* p) {
    cout << "int* overload
";
}

int main() {
    foo(0);
    foo(nullptr);
    return 0;
}

Explanation & Logic Summary:

0 is an integer literal, so overload resolution selects foo(int).
nullptr has type std::nullptr_t and converts only to pointer types, so foo(int*) is selected.
This behavior is guaranteed by the C++ standard, unlike NULL.

Firmware Relevance & Real-World Context:

Firmware APIs often overload functions for:
- Scalar configuration values
- Pointer-based buffers or structures
Using nullptr instead of integer literals or macros prevents:
- Accidental selection of the wrong overload
- Subtle runtime bugs caused by incorrect API paths
This practice improves type safety, readability, and portability in embedded C++ code.

36. Overload Resolution Trap