Struct xcm_builder::CurrencyAdapter

pub struct CurrencyAdapter<Currency, Matcher, AccountIdConverter, AccountId, CheckedAccount>(_);

Simple adapter to use a currency as asset transactor. This type can be used as type AssetTransactor in xcm::Config.

Example

use parity_scale_codec::Decode;
use frame_support::{parameter_types, PalletId};
use sp_runtime::traits::{AccountIdConversion, TrailingZeroInput};
use xcm::latest::prelude::*;
use xcm_builder::{ParentIsPreset, CurrencyAdapter, IsConcrete};

/// Our chain's account id.
type AccountId = sp_runtime::AccountId32;

/// Our relay chain's location.
parameter_types! {
    pub RelayChain: MultiLocation = Parent.into();
    pub CheckingAccount: AccountId = PalletId(*b"checking").into_account_truncating();
}

/// Some items that implement `ConvertLocation<AccountId>`. Can be more, but for now we just assume we accept
/// messages from the parent (relay chain).
pub type LocationConverter = (ParentIsPreset<AccountId>);

/// Just a dummy implementation of `Currency`. Normally this would be `Balances`.
pub type CurrencyImpl = ();

/// Final currency adapter. This can be used in `xcm::Config` to specify how asset related transactions happen.
pub type AssetTransactor = CurrencyAdapter<
    // Use this `Currency` impl instance:
    CurrencyImpl,
    // The matcher: use the currency when the asset is a concrete asset in our relay chain.
    IsConcrete<RelayChain>,
    // The local converter: default account of the parent relay chain.
    LocationConverter,
    // Our chain's account ID type.
    AccountId,
    // The checking account. Can be any deterministic inaccessible account.
    CheckingAccount,
>;

Trait Implementations

impl<Currency: Currency<AccountId>, Matcher: MatchesFungible<Currency::Balance>, AccountIdConverter: ConvertLocation<AccountId>, AccountId: Clone, CheckedAccount: Get<Option<(AccountId, MintLocation)>>> TransactAsset for CurrencyAdapter<Currency, Matcher, AccountIdConverter, AccountId, CheckedAccount>

fn can_check_in( _origin: &MultiLocation, what: &MultiAsset, _context: &XcmContext ) -> Result

Ensure that check_in will do as expected.

fn check_in(_origin: &MultiLocation, what: &MultiAsset, _context: &XcmContext)

An asset has been teleported in from the given origin. This should do whatever housekeeping is needed.

fn can_check_out( _dest: &MultiLocation, what: &MultiAsset, _context: &XcmContext ) -> Result

Ensure that check_out will do as expected.

fn check_out(_dest: &MultiLocation, what: &MultiAsset, _context: &XcmContext)

An asset has been teleported out to the given destination. This should do whatever housekeeping is needed.

fn deposit_asset( what: &MultiAsset, who: &MultiLocation, _context: &XcmContext ) -> Result

Deposit the what asset into the account of who.

fn withdraw_asset( what: &MultiAsset, who: &MultiLocation, _maybe_context: Option<&XcmContext> ) -> Result<Assets, XcmError>

Withdraw the given asset from the consensus system. Return the actual asset(s) withdrawn, which should always be equal to _what.

fn internal_transfer_asset( asset: &MultiAsset, from: &MultiLocation, to: &MultiLocation, _context: &XcmContext ) -> Result<Assets, XcmError>

Move an asset from one location in to another location.

fn transfer_asset( asset: &MultiAsset, from: &MultiLocation, to: &MultiLocation, context: &XcmContext ) -> Result<Assets, Error>

Move an asset from one location in to another location.