Test of C++ fold expressions.

fold.cpp

#include <iostream>

using namespace std;

constexpr auto all(auto&&... args) {
    return (args && ...);
}

int main() {
    cout << boolalpha;

    cout << all() << endl;
    cout << all(true) << endl;
    cout << all(false) << endl;
    cout << all(true, true) << endl;
    cout << all(true, false) << endl;
    cout << all(false, true, true) << endl;
}