#include <iostream>

#define BLOCK(x) BLOCK_I x
#define OPEN )
#define BLOCK_I()
#define END END_I(
#define END_I()

#define STR(a) STR_I(a)
#define STR_I(a) #a

int main() {
    using namespace std;
    cout << STR(BLOCK((OPEN { return f(1, 2); } END))) << endl;
}

{ return f(1, 2); }