Challenge 1: A Function That Throws on a Negative Input — Possible Solution
====================================================================

#include <iostream>
#include <stdexcept>

void check_positive(int value) {
    if (value < 0) {
        throw std::runtime_error("value must not be negative");
    }
    std::cout << "Value is fine: " << value << std::endl;
}

int main() {
    try {
        check_positive(-5);
    } catch (const std::exception &e) {
        std::cout << "Caught: " << e.what() << std::endl;
    }

    return 0;
}

Output:

    Caught: value must not be negative

WHY THIS WORKS AS AN ANSWER
------------------------------
check_positive(-5) triggers the throw std::runtime_error(...) line
before ever reaching the "fine" message, and control transfers
immediately to the matching catch (const std::exception&) block in
main -- e.what() returns the message string passed to the
runtime_error's own constructor, confirming the exception carried the
correct information through to the catch site.