Checking the code further, I found that we are actually already checking if same currency in bank#exchange_with (https://github.com/RubyMoney/money/blob/master/lib/money/bank/variable_exchange.rb#L88) which is called from money#exchange_to so that for me it's safe to just shorten the code like this:
```ruby
 def +(other_money)
     Money.new(fractional + other_money.exchange_to(currency).fractional, currency)
   end
```
How do you guys think?