enum-without-for-and-if.cpp

#include <functional>
#include <iostream>
using namespace std;

void cond(bool condition, function<void()> ifTrue, function<void()> ifFalse) {
    function<void()> branches[] = {ifFalse, ifTrue};
    branches[condition]();
}

template <typename T>
void enumerateDo(T start, T step, T stop, void action(int)) {
    cond(
        start <= stop,
        [=]{
            action(start);
            enumerateDo(start + step, step, stop, action);
        },
        []{}
    );
}

int main() {
    enumerateDo(3, 2, 10, [](int x){cout << x << ' ';});
    cout << endl;
    return 0;
}