#include <iostream>
#include <functional>

std::function<int()> make_adder(int x1)
{
    return [&x1]() {
        return x1 + 1;
    };
}

int main()
{
    auto add_one = make_adder(5);
    std::cout << add_one() << std::endl; // This will likely cause a crash or undefined behavior
    return 0;
}