How is the Etherscan TokenTracker able to show holder addresses? The
balances mapping of your average ERC20 token cannot be iterated over by index, nor can the length of the
mapping be obtained. So how might holder address information be available to Etherscan?
For example, you can view the Gnosis TokenTracker here and confirm a list of holders.
Next, if you view the contract source, you'll see that there's no code that explicitly returns the holder
address by way of reference to
mapping (address => uint256) balances or anything else. (At least not that I can see.
Many thanks in advance for your help.