First run

firstRun.cpp

#include <stdio.h>

int main(int argc, const char * argv[]) {
  
  struct FirstRun {
    bool hasRun = 0;
    
    operator bool() {
      bool firstRun = !hasRun;
      hasRun = 1;
      return firstRun;
    }
  };
  
  for (int i = 0; i < 3; i++) {
    static FirstRun isFirstRun;
    if (isFirstRun)  puts("1st run");
    else puts("subsequent");
  }
  
  return 0;  
}