533: Mainline

Because you have told C++ that the capacity function returns a floating-point number, C++ can determine how to handle capacity in output statements. Accordingly, you can rewrite the for loop as follows:

for (n = 0; n < car_count; ++n) {
  // Display short name, such as eng, box, tnk, or cab:
  train[n] -> display_short_name ( );
  // Display spaces:
  cout << "     ";
  // Display load capacity, and terminate the line:  
  cout << train[n] -> capacity ( ) << endl;         
}