public static PiggyBankImmutable BuyCandy(PiggyBankImmutable piggyBank)
{
if (piggyBank.Coins < 7)
throw new ArgumentException(
"Not enough money for candy!", "piggyBank");
return new PiggyBankImmutable(piggyBank.Coins - 7);
}
public static void TestImmutable()
{
// still raises an ArgumentException
var piggyBank = new PiggyBankImmutable(5);
// ImmutableTest.BuyCandy(piggyBank);
// ImmutableTest.DepositCoins(piggyBank);
// now this raises an ArgumentException, too!
piggyBank = new PiggyBankImmutable(5);
ImmutableTest.DepositCoins(piggyBank);
ImmutableTest.BuyCandy(piggyBank);
piggyBank = new PiggyBankImmutable(5);
ImmutableTest.BuyCandy(ImmutableTest.DepositCoins(piggyBank));
}
public static PiggyBankImmutable DepositCoins(PiggyBankImmutable piggyBank)
{
return new PiggyBankImmutable(piggyBank.Coins + 10);
}
