Module xcm::v1

Expand description

XCM Version 1

Version 1 of the Cross-Consensus Message format data structures. The comprehensive list of changes can be found in this PR description.

Most changes should automatically be resolved via the conversion traits (i.e. TryFrom and From). The list here is mostly for incompatible changes that result in an Err(()) when attempting to convert XCM objects from v0.

Junction

v0::Junction::Parent cannot be converted to v1, because the way we represent parents in v1 has changed - instead of being a property of the junction, v1 MultiLocations now have an extra field representing the number of parents that the MultiLocation contains.

`MultiLocation`

The try_from conversion method will always canonicalize the v0 MultiLocation before attempting to do the proper conversion. Since canonicalization is not a fallible operation, we do not expect v0 MultiLocation to ever fail to be upgraded to v1.

`MultiAsset`

Stronger typing to differentiate between a single class of MultiAsset and several classes of MultiAssets is introduced. As the name suggests, a Vec<MultiAsset> that is used on all APIs will instead be using a new type called MultiAssets (note the s).
All MultiAsset variants whose name contains “All” in it, namely v0::MultiAsset::All, v0::MultiAsset::AllFungible, v0::MultiAsset::AllNonFungible, v0::MultiAsset::AllAbstractFungible, v0::MultiAsset::AllAbstractNonFungible, v0::MultiAsset::AllConcreteFungible and v0::MultiAsset::AllConcreteNonFungible, will fail to convert to v1 MultiAsset, since v1 does not contain these variants.
Similarly, all MultiAsset variants whose name contains “All” in it can be converted into a WildMultiAsset.
v0::MultiAsset::None is not represented at all in v1.

XCM

No special attention necessary

Order

v1::Order::DepositAsset and v1::Order::DepositReserveAsset both introduced a new max_asset field that limits the maximum classes of assets that can be deposited. During conversion from v0, the max_asset field defaults to 1.
v1 Orders that contain MultiAsset as argument(s) will need to explicitly specify the amount and details of assets. This is to prevent accidental misuse of All to possibly transfer, spend or otherwise perform unintended operations on All assets.
v1 Orders that do allow the notion of All to be used as wildcards, will instead use a new type called MultiAssetFilter.

Re-exports

pub use super::v0::OriginKind;

Modules

opaque

prelude

A prelude for importing all types typically used when interacting with XCM messages.

Structs

Ancestor

A unit struct which can be converted into a MultiLocation of the inner parents value.

AncestorThen

A unit struct which can be converted into a MultiLocation of the inner parents value and the inner interior.

MultiAsset

MultiAssets

A Vec of MultiAssets. There may be no duplicate fungible items in here and when decoding, they must be sorted.

MultiLocation

A relative path between state-bearing consensus systems.

Parent

A unit struct which can be converted into a MultiLocation of parents value 1.

ParentThen

A tuple struct which can be converted into a MultiLocation of parents value 1 with the inner interior.

Enums

AssetId

Classification of an asset being concrete or abstract.

AssetInstance

A general identifier for an instance of a non-fungible asset class.

BodyId

An identifier of a pluralistic body.

BodyPart

A part of a pluralistic body.

Error

Fungibility

Classification of whether an asset is fungible or not, along with a mandatory amount or instance.

Junction

A single item in a path to describe the relative location of a consensus system.

Junctions

Non-parent junctions that can be constructed, up to the length of 8. This specific Junctions implementation uses a Rust enum in order to make pattern matching easier.

MultiAssetFilter

MultiAsset collection, either MultiAssets or a single wildcard.

NetworkId

A global identifier of an account-bearing consensus system.

Order

An instruction to be executed on some or all of the assets in holding, used by asset-related XCM messages.

Outcome

Outcome of an XCM execution.

Response

Response data to a query.

WildFungibility

Classification of whether an asset is fungible or not.