program foo()
  var i := 1;
  var s1 := struct{ i := i };
  var s2 := struct{};
  var s3 := struct{};
  var s4 := struct{};
  s2.+i := i;
  s3.insert( "i", i );
  s4["i"] := i;
  i += 1;
  print( i );
  print( s1 ); // structs should not change
  print( s2 );
  print( s3 );
  print( s4 );
endprogram