#include <iostream>
 
// Source - https://stackoverflow.com/a/10616756
// Posted by Jon, modified by community. See post 'Timeline' for change history
// Retrieved 2025-12-12, License - CC BY-SA 3.0
 
#define OUT(x) if((x > 0 ? cout << "Hello " : cout), x > 1) cout << x+1
 
 
using namespace std;
 
int main() {
OUT(1) << "message";     // OK
 
if(0) {
   OUT(1) << "message";     // OK, nothing printed
}
 
if(0)
   OUT(1) << "message";     // Now nothing is printed
 
	return 0;
}

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