exercism/cpp/vehicle-purchase/vehicle_purchase.cpp

#include "vehicle_purchase.h"
#include <cctype>
#include <string>

namespace vehicle_purchase {

// needs_license determines whether a license is needed to drive a type of
// vehicle. Only "car" and "truck" require a license.
bool needs_license(std::string kind) {
  return (kind == "car") || (kind == "truck");
}

// choose_vehicle recommends a vehicle for selection. It always recommends the
// vehicle that comes first in lexicographical order.
std::string choose_vehicle(std::string option1, std::string option2) {
  std::string suffix{" is clearly the better choice."};
  return (option1 > option2) ? option2 + suffix : option1 + suffix;
}

// calculate_resell_price calculates how much a vehicle can resell for at a
// certain age.
double calculate_resell_price(double original_price, double age) {

  if (age < 3) {
    original_price *= 0.8;
  } else if (age >= 10) {
    original_price *= 0.5;
  } else {
    original_price *= 0.7;
  }

  return original_price;
}

} // namespace vehicle_purchase