Besides, euros et al. are all fiat currency, including the Chinese yuan. All will fail, so if you have a gun safe full of any modern currency, it will fail. Period.
Again, look up the bancor - invented as a concept by Keynes, and quite possibly where we are headed after the collapse - which will make everyone who sold short tons of wealth.
My first thought on reading this was - boy, that didn't take long. Wonder what sucker country China found to buy the trillions in t-bills they once held?