#include <stdio.h>
#define TEST(condition, ...)                                                   \
  ((condition) ? printf("Passed test: %s\n", #condition) : printf(__VA_ARGS__))

int main() {
  int voltage = 30;
  int max_voltage = 20;
  TEST(voltage <= max_voltage, "Voltage %d exceeds %d\n", voltage, max_voltage);
  max_voltage = 40;
  TEST(voltage <= max_voltage, "Voltage %d exceeds %d\n", voltage, max_voltage);
}