Hello CodeForces community!

Recently I've recalled one interesting C++ problem. In short: is it possible to write functions action and cond in such a way, so that the following code snippets work differently:

// Snippet #1:
action();
while (cond()) {
    action();
}

// Snippet #2:
do {
    action();
} while (cond());

More formally: suppose you're given the following three files:

#include <iostream>

bool cond() {}

void action() {
    std::cout << "Action" << std::endl;
}

#include "common.h"

int main() {
    action();
    while (cond()) {
        action();
    }
    return 0;
}

#include "common.h"

int main() {
    do {
        action();
    } while (cond());
    return 0;
}

You're only allowed to modify common.h. You have to do that in such a way, so that Action word is printed different amount of times by execution of main_while.cpp and main_do_while.cpp.

One of the possible solutions (try to think yourself before opening the spoiler!):

#include <iostream>

bool cond() {
    #define do if(true)
    static int attempt = 0;
    attempt++;
    return attempt % 2 != 0;
}

void action() {
    std::cout << "Action" << std::endl;
}

Share your solutions in the comments and don't forget to hide them under the spoilers! It would be interesting to see something smarter (e.g. solution which will work in any language with analogues of while and do-while)