Module frame_support::storage::types[][src]

Expand description

Storage types to build abstraction on storage, they implements storage traits such as StorageMap and others.


A wrapper around a StorageMap and a StorageValue<Value=u32> to keep track of how many items are in a map, without needing to iterate all the values.

A type used exclusively by storage maps as their key type.

Implement QueryKindTrait with query being Option<Value>

A type that allow to store values for (key1, key2) couple. Similar to StorageMap but allow to iterate and remove value associated to first key.

A type that allow to store value for given key. Allowing to insert/remove/iterate on values.

A type that allow to store values for an arbitrary number of keys in the form of (Key<Hasher1, key1>, Key<Hasher2, key2>, ..., Key<HasherN, keyN>).

A type that allow to store a value.

Implement QueryKindTrait with query being Value


The requirement for an instance of CountedStorageMap.

Marker trait to indicate that each element in the tuple encodes like the corresponding element in another tuple.

Trait indicating whether a KeyGenerator has the prefix P.

Trait indicating whether a ReversibleKeyGenerator has the prefix P.

A trait that contains the current key as an associated type.

The maximum length used by the key in storage.

Trait implementing how the storage optional value is converted into the queried type.

A trait that indicates the hashers for the keys generated are all reversible.

Build the metadata of a storage.

Trait to indicate that a tuple can be converted into an iterator of a vector of encoded bytes.