Trait frame_support::traits::tokens::fungible::hold::Unbalanced
source · pub trait Unbalanced<AccountId>: Inspect<AccountId> {
// Required method
fn set_balance_on_hold(
reason: &Self::Reason,
who: &AccountId,
amount: Self::Balance
) -> DispatchResult;
// Provided methods
fn decrease_balance_on_hold(
reason: &Self::Reason,
who: &AccountId,
amount: Self::Balance,
precision: Precision
) -> Result<Self::Balance, DispatchError> { ... }
fn increase_balance_on_hold(
reason: &Self::Reason,
who: &AccountId,
amount: Self::Balance,
precision: Precision
) -> Result<Self::Balance, DispatchError> { ... }
}
Expand description
A fungible, holdable token class where the balance on hold 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 inflation 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§
sourcefn set_balance_on_hold(
reason: &Self::Reason,
who: &AccountId,
amount: Self::Balance
) -> DispatchResult
fn set_balance_on_hold( reason: &Self::Reason, who: &AccountId, amount: Self::Balance ) -> DispatchResult
Forcefully set the balance on hold of who
to amount
. This is independent of any other
balances on hold or the main (“free”) balance.
If this call executes successfully, you can assert_eq!(Self::balance_on_hold(), amount);
.
This function does its best to force the balance change through, but will not break system
invariants such as any Existential Deposits needed or overflows/underflows.
If this cannot be done for some reason (e.g. because the account doesn’t exist) then an
Err
is returned.
Provided Methods§
sourcefn decrease_balance_on_hold(
reason: &Self::Reason,
who: &AccountId,
amount: Self::Balance,
precision: Precision
) -> Result<Self::Balance, DispatchError>
fn decrease_balance_on_hold( reason: &Self::Reason, who: &AccountId, amount: Self::Balance, precision: Precision ) -> Result<Self::Balance, DispatchError>
Reduce the balance on hold of who
by amount
.
If precision
is Exact
and it cannot be reduced by that amount for
some reason, return Err
and don’t reduce it at all. If precision
is BestEffort
, then
reduce the balance of who
by the most that is possible, up to amount
.
In either case, if Ok
is returned then the inner is the amount by which is was reduced.
sourcefn increase_balance_on_hold(
reason: &Self::Reason,
who: &AccountId,
amount: Self::Balance,
precision: Precision
) -> Result<Self::Balance, DispatchError>
fn increase_balance_on_hold( reason: &Self::Reason, who: &AccountId, amount: Self::Balance, precision: Precision ) -> Result<Self::Balance, DispatchError>
Increase the balance on hold 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.