#include <iostream>
#include <string>

struct pair{double x, y;};

int main(){
  int var = 5,
      tab1[7],
      *tab2;
  pair tab3[5];

  // ...

  var = 7;
  tab1[3] = 8;
  *(tab2 + 4) = 9;
  tab3[0].x = 2.0;

}