decl_storage macro to define type-safe, persistent data that needs to be stored on-chain.
For cryptocurrencies, storage might consist of a mapping between account keys and corresponding balances.
More generally, blockchains provide an interface to store and interact with data in a verifiable and globally irreversible way. In this context, data is stored in a series of snapshots, each of which may be accessed at a later point in time, but, once created, snapshots are considered irreversible.
- Single Value Storage
- Simple Token Transfer (Maps)
- Lists as Maps
- Nested Structs
- Social Network (Higher Order Arrays)