Trait frame_support::traits::tokens::fungible::Unbalanced

pub trait Unbalanced<AccountId>: Inspect<AccountId> {
    fn set_balance(who: &AccountId, amount: Self::Balance) -> DispatchResult;
    fn set_total_issuance(amount: Self::Balance);

    fn decrease_balance(
        who: &AccountId, 
        amount: Self::Balance
    ) -> Result<Self::Balance, DispatchError> { ... }
    fn decrease_balance_at_most(
        who: &AccountId, 
        amount: Self::Balance
    ) -> Self::Balance { ... }
    fn increase_balance(
        who: &AccountId, 
        amount: Self::Balance
    ) -> Result<Self::Balance, DispatchError> { ... }
    fn increase_balance_at_most(
        who: &AccountId, 
        amount: Self::Balance
    ) -> Self::Balance { ... }
}

A fungible token class where the balance can be set arbitrarily.

WARNING Do not use this directly unless you want trouble, since it allows you to alter account balances without keeping the issuance up to date. It has no safeguards against accidentally creating token imbalances in your system leading to accidental imflation or deflation. It’s really just for the underlying datatype to implement so the user gets the much safer Balanced trait to use.

Required methods

fn set_balance(who: &AccountId, amount: Self::Balance) -> DispatchResult

Set the balance of who to amount. If this cannot be done for some reason (e.g. because the account cannot be created or an overflow) then an Err is returned.

fn set_total_issuance(amount: Self::Balance)

Set the total issuance to amount.

Provided methods

fn decrease_balance(
    who: &AccountId,
    amount: Self::Balance
) -> Result<Self::Balance, DispatchError>

Reduce the balance of who by amount. If it cannot be reduced by that amount for some reason, return Err and don’t reduce it at all. If Ok, return the imbalance.

Minimum balance will be respected and the returned imbalance may be up to Self::minimum_balance() - 1 greater than amount.

fn decrease_balance_at_most(
    who: &AccountId,
    amount: Self::Balance
) -> Self::Balance

Reduce the balance of who by the most that is possible, up to amount.

Minimum balance will be respected and the returned imbalance may be up to Self::minimum_balance() - 1 greater than amount.

Return the imbalance by which the account was reduced.

fn increase_balance(
    who: &AccountId,
    amount: Self::Balance
) -> Result<Self::Balance, DispatchError>

Increase the balance of who by amount. If it cannot be increased by that amount for some reason, return Err and don’t increase it at all. If Ok, return the imbalance.

Minimum balance will be respected and an error will be returned if amount < Self::minimum_balance() when the account of who is zero.

fn increase_balance_at_most(
    who: &AccountId,
    amount: Self::Balance
) -> Self::Balance

Increase the balance of who by the most that is possible, up to amount.

Minimum balance will be respected and the returned imbalance will be zero in the case that amount < Self::minimum_balance().

Return the imbalance by which the account was increased.

Implementors

impl<F: Unbalanced<AccountId>, A: Get<<F as Inspect<AccountId>>::AssetId>, AccountId> Unbalanced<AccountId> for ItemOf<F, A, AccountId>