gistfile1.cpp

// v1
#define loop(x,op,y) (auto t=x; for(auto c=y;c>1;--c){t=t op;},t)

//v2
#define rdo(x,op,y) ([&](){auto t=x;auto r=y;while(r){t=t op;};return t;})()

//v3
#define rdo(x,op,y) (auto l=[=](){auto t=x;auto r=y;while(r){t=t op;};return t;},l())

//v4
#define rdo(x,op,y) (auto l=[=](){auto t=x;auto r=y;while(r){t=t op;--r};return t;},l())

printf("%d", rdo(2,*2,2));