DrainableCurrency

[4meta5]

pub trait DrainableCurrency<AccountId, Weight> {
    fn drain_to_accounts(
        from: &AccountId,
        to_accounts: OrderedSet<AccountId>,
    ) -> DispatchResult;

    fn drain_to_accounts_weighted(
        from: &AccountId,
        to_weighted_accounts: OrderedSet<(AccountId, Weight)>,
    ) -> DispatchResult;
}

We use this logic in

• donate (which is used in bank)
• kickback and it is planned to be used in bounty2

donate requires a remainder_recipient input for collecting the remainder. We could add

1. implementation that chooses an AccountId from recipient_accounts at random to send the remainder
2. implementation that spreads the remainder among a random subset of the recipient_accounts

The remainder will exist in most cases so the question is what to do with it...