Cash might provide you with the opportunity to buy at lower prices. At some point there will be a critical mass of people who start to see currency as worthless debt and realise the value of gold. This will occur as a result of a system breakdown, more than likely triggered by a derivatives collapse. Everything (including currency) is built on debt. The only safe haven during a debt collapse will be gold (and other valuable, storable assets). Crypto currencies will also benefit to some extent, but as people rush out of risk assets they will prefer gold to crypto's.
RE: Why Harry Dent is both right and wrong on deflation