Что выведет: вектор колбэков и IIFE

#include <functional>
#include <iostream>
#include <vector>

int main() {
    std::vector<std::function<int()>> fs;
    for (int i = 0; i < 3; ++i) fs.push_back([i] { return i * i; });
    for (auto& f : fs) std::cout << f();
    std::cout << '\n';
    const int total = [] {
        int s = 0;
        for (int i = 1; i <= 4; ++i) s += i;
        return s;
    }();
    std::cout << total << '\n';
    std::function<void()> empty;
    try {
        empty();
    } catch (const std::bad_function_call&) {
        std::cout << "bad call\n";
    }
}