Module prelude

The main prelude of FRAME.

This prelude should almost always be the first line of code in any pallet or runtime.

use polkadot_sdk_frame::prelude::*;

// rest of your pallet..
mod pallet {}

Re-exports

• pub use frame_support::dispatch::GetDispatchInfo;
• pub use frame_support::dispatch::PostDispatchInfo;
• pub use sp_runtime::traits::AccountIdConversion;
• pub use sp_runtime::traits::BlockNumberProvider;
• pub use sp_runtime::traits::Bounded;
• pub use sp_runtime::traits::Convert;
• pub use sp_runtime::traits::ConvertBack;
• pub use sp_runtime::traits::DispatchInfoOf;
• pub use sp_runtime::traits::Dispatchable;
• pub use sp_runtime::traits::ReduceBy;
• pub use sp_runtime::traits::ReplaceWithDefault;
• pub use sp_runtime::traits::SaturatedConversion;
• pub use sp_runtime::traits::Saturating;
• pub use sp_runtime::traits::StaticLookup;
• pub use sp_runtime::traits::TrailingZeroInput;
• pub use sp_runtime::BoundToRuntimeAppPublic;
• pub use sp_runtime::DispatchErrorWithPostInfo;
• pub use sp_runtime::DispatchResultWithInfo;
• pub use sp_runtime::TokenError;
• pub use frame_support::pallet_prelude::*;
• pub use frame_system::pallet_prelude::*;
• pub use frame_system::offchain::*;
• pub use super::derive::*;
• pub use super::hashing::*;
• pub use super::account::*;
• pub use super::arithmetic::*;
• pub use super::token::*;

Modules

• frame_system
  frame_system’s parent crate, which is mandatory in all pallets build with this crate.

Structs

• BoundedSlice
  Bounded storage related types. A bounded slice.
• BoundedVec
  Bounded storage related types. A bounded vector.
• EitherOf
  “OR gate” implementation of EnsureOrigin, Success type for both L and R must be equal.
• MapSuccess
  A derivative EnsureOrigin implementation. It mutates the Success result of an Original implementation with a given Mutator.
• NoOpPoll
  NoOp polling is required if pallet-referenda functionality not needed.
• PalletId
  A pallet identifier. These are per pallet and should be stored in a registry somewhere.
• VariantCountOf
  Adapter for Get<u32> to access VARIANT_COUNT from trait pub trait VariantCount {.

Enums

• Everything
  A Contains implementation that contains every value.

Traits

• Contains
  A trait for querying whether a type can be said to “contain” a value.
• Defensive
  A trait to handle errors and options when you are really sure that a condition must hold, but not brave enough to expect on it, or a default fallback value makes more sense.
• DefensiveSaturating
  A variant of Defensive with the same rationale, for the arithmetic operations where in case an infallible operation fails, it saturates.
• EstimateNextSessionRotation
  Something that can estimate at which block the next session rotation will happen (i.e. a new session starts).
• IsSubType
  Something that can be checked to be a of sub type T.
• OnRuntimeUpgrade
  See Hooks::on_runtime_upgrade.
• OneSessionHandler
  A session handler for specific key type.
• RankedMembers
  Ranked membership data structure.
• RankedMembersSwapHandler
  Handler that can deal with the swap of two members.
• VariantCount
  Trait to get the number of variants in any enum.