lib.rs

// This file is part of Substrate.

// Copyright (C) 2017-2022 Parity Technologies (UK) Ltd.
// SPDX-License-Identifier: Apache-2.0

// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// 	http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

//! Support code for the runtime.
//!
//! ## Note on Tuple Traits
//!
//! Many of the traits defined in [`traits`] have auto-implementations on tuples as well. Usually,
//! the tuple is a function of number of pallets in the runtime. By default, the traits are
//! implemented for tuples of up to 64 items.
//
// If you have more pallets in your runtime, or for any other reason need more, enabled `tuples-96`
// or the `tuples-128` complication flag. Note that these features *will increase* the compilation
// of this crate.

#![cfg_attr(not(feature = "std"), no_std)]

/// Export ourself as `frame_support` to make tests happy.
extern crate self as frame_support;

#[doc(hidden)]
pub use sp_tracing;

#[doc(hidden)]
pub use codec;
#[doc(hidden)]
pub use frame_metadata as metadata;
#[doc(hidden)]
pub use log;
#[cfg(feature = "std")]
#[doc(hidden)]
pub use once_cell;
#[doc(hidden)]
pub use paste;
#[doc(hidden)]
pub use scale_info;
#[cfg(feature = "std")]
pub use serde;
pub use sp_core::Void;
#[doc(hidden)]
pub use sp_core_hashing_proc_macro;
#[doc(hidden)]
pub use sp_io::{self, storage::root as storage_root};
#[cfg(feature = "std")]
#[doc(hidden)]
pub use sp_runtime::{bounded_btree_map, bounded_vec};
#[doc(hidden)]
pub use sp_runtime::{RuntimeDebug, StateVersion};
#[cfg(feature = "std")]
#[doc(hidden)]
pub use sp_state_machine::BasicExternalities;
#[doc(hidden)]
pub use sp_std;
#[doc(hidden)]
pub use tt_call::*;

#[macro_use]
pub mod dispatch;
mod hash;
pub mod storage;
#[macro_use]
pub mod event;
pub mod inherent;
#[macro_use]
pub mod error;
pub mod crypto;
pub mod instances;
pub mod migrations;
pub mod traits;
pub mod weights;

#[doc(hidden)]
pub mod unsigned {
	#[doc(hidden)]
	pub use crate::sp_runtime::traits::ValidateUnsigned;
	#[doc(hidden)]
	pub use crate::sp_runtime::transaction_validity::{
		TransactionSource, TransactionValidity, TransactionValidityError, UnknownTransaction,
	};
}

#[cfg(any(feature = "std", feature = "runtime-benchmarks", feature = "try-runtime", test))]
pub use self::storage::storage_noop_guard::StorageNoopGuard;
pub use self::{
	dispatch::{Callable, Parameter},
	hash::{
		Blake2_128, Blake2_128Concat, Blake2_256, Hashable, Identity, ReversibleStorageHasher,
		StorageHasher, Twox128, Twox256, Twox64Concat,
	},
	storage::{
		bounded_btree_map::BoundedBTreeMap,
		bounded_btree_set::BoundedBTreeSet,
		bounded_vec::{BoundedSlice, BoundedVec},
		migration,
		weak_bounded_vec::WeakBoundedVec,
		IterableStorageDoubleMap, IterableStorageMap, IterableStorageNMap, StorageDoubleMap,
		StorageMap, StorageNMap, StoragePrefixedMap, StorageValue,
	},
};
pub use sp_runtime::{
	self, print, traits::Printable, ConsensusEngineId, MAX_MODULE_ERROR_ENCODED_SIZE,
};

use codec::{Decode, Encode};
use scale_info::TypeInfo;
use sp_runtime::TypeId;

/// A unified log target for support operations.
pub const LOG_TARGET: &str = "runtime::frame-support";

/// A type that cannot be instantiated.
#[derive(Encode, Decode, Debug, PartialEq, Eq, Clone, TypeInfo)]
pub enum Never {}

/// A pallet identifier. These are per pallet and should be stored in a registry somewhere.
#[derive(Clone, Copy, Eq, PartialEq, Encode, Decode, TypeInfo)]
pub struct PalletId(pub [u8; 8]);

impl TypeId for PalletId {
	const TYPE_ID: [u8; 4] = *b"modl";
}

/// Generate a new type alias for [`storage::types::StorageValue`],
/// [`storage::types::StorageMap`], [`storage::types::StorageDoubleMap`]
/// and [`storage::types::StorageNMap`].
///
/// Useful for creating a *storage-like* struct for test and migrations.
///
/// ```
/// # use frame_support::storage_alias;
/// use frame_support::codec;
/// use frame_support::Twox64Concat;
/// // generate a storage value with type u32.
/// #[storage_alias]
/// type StorageName = StorageValue<Prefix, u32>;
///
/// // generate a double map from `(u32, u32)` (with hashers `Twox64Concat` for each key)
/// // to `Vec<u8>`
/// #[storage_alias]
/// type OtherStorageName = StorageDoubleMap<
/// 	OtherPrefix,
/// 	Twox64Concat,
/// 	u32,
/// 	Twox64Concat,
/// 	u32,
/// 	Vec<u8>,
/// >;
///
/// // optionally specify the query type
/// use frame_support::pallet_prelude::{ValueQuery, OptionQuery};
/// #[storage_alias]
/// type ValueName = StorageValue<Prefix, u32, OptionQuery>;
/// #[storage_alias]
/// type SomeStorageName = StorageMap<
/// 	Prefix,
/// 	Twox64Concat,
/// 	u32,
/// 	Vec<u8>,
/// 	ValueQuery,
/// >;
///
/// // generate a map from `Config::AccountId` (with hasher `Twox64Concat`) to `Vec<u8>`
/// trait Config { type AccountId: codec::FullCodec; }
/// #[storage_alias]
/// type GenericStorage<T> = StorageMap<Prefix, Twox64Concat, <T as Config>::AccountId, Vec<u8>>;
///
/// // It also supports NMap
/// use frame_support::storage::types::Key as NMapKey;
///
/// #[storage_alias]
/// type SomeNMap = StorageNMap<Prefix, (NMapKey<Twox64Concat, u32>, NMapKey<Twox64Concat, u64>), Vec<u8>>;
///
/// // Using pallet name as prefix.
/// //
/// // When the first generic argument is taking generic arguments it is expected to be a pallet.
/// // The prefix will then be the pallet name as configured in the runtime through
/// // `construct_runtime!`.
///
/// # struct Pallet<T: Config, I = ()>(std::marker::PhantomData<(T, I)>);
/// # impl<T: Config, I: 'static> frame_support::traits::PalletInfoAccess for Pallet<T, I> {
/// # 	fn index() -> usize { 0 }
/// # 	fn name() -> &'static str { "pallet" }
/// # 	fn module_name() -> &'static str { "module" }
/// # 	fn crate_version() -> frame_support::traits::CrateVersion { unimplemented!() }
/// # }
///
/// #[storage_alias]
/// type SomeValue<T: Config> = StorageValue<Pallet<T>, u64>;
///
/// // Pallet with instance
///
/// #[storage_alias]
/// type SomeValue2<T: Config, I: 'static> = StorageValue<Pallet<T, I>, u64>;
///
/// # fn main() {}
/// ```
pub use frame_support_procedural::storage_alias;

/// Create new implementations of the [`Get`](crate::traits::Get) trait.
///
/// The so-called parameter type can be created in four different ways:
///
/// - Using `const` to create a parameter type that provides a `const` getter. It is required that
///   the `value` is const.
///
/// - Declare the parameter type without `const` to have more freedom when creating the value.
///
/// - Using `storage` to create a storage parameter type. This type is special as it tries to load
///   the value from the storage under a fixed key. If the value could not be found in the storage,
///   the given default value will be returned. It is required that the value implements
///   [`Encode`](codec::Encode) and [`Decode`](codec::Decode). The key for looking up the value in
///   the storage is built using the following formula:
///
///   `twox_128(":" ++ NAME ++ ":")` where `NAME` is the name that is passed as type name.
///
/// - Using `static` to create a static parameter type. Its value is being provided by a static
///   variable with the equivalent name in `UPPER_SNAKE_CASE`. An additional `set` function is
///   provided in this case to alter the static variable. **This is intended for testing ONLY and is
///   ONLY available when `std` is enabled.**
///
/// # Examples
///
/// ```
/// # use frame_support::traits::Get;
/// # use frame_support::parameter_types;
/// // This function cannot be used in a const context.
/// fn non_const_expression() -> u64 { 99 }
///
/// const FIXED_VALUE: u64 = 10;
/// parameter_types! {
///    pub const Argument: u64 = 42 + FIXED_VALUE;
///    /// Visibility of the type is optional
///    OtherArgument: u64 = non_const_expression();
///    pub storage StorageArgument: u64 = 5;
///    pub static StaticArgument: u32 = 7;
/// }
///
/// trait Config {
///    type Parameter: Get<u64>;
///    type OtherParameter: Get<u64>;
///    type StorageParameter: Get<u64>;
///    type StaticParameter: Get<u32>;
/// }
///
/// struct Runtime;
/// impl Config for Runtime {
///    type Parameter = Argument;
///    type OtherParameter = OtherArgument;
///    type StorageParameter = StorageArgument;
///    type StaticParameter = StaticArgument;
/// }
///
/// // In testing, `StaticArgument` can be altered later: `StaticArgument::set(8)`.
/// ```
///
/// # Invalid example:
///
/// ```compile_fail
/// # use frame_support::traits::Get;
/// # use frame_support::parameter_types;
/// // This function cannot be used in a const context.
/// fn non_const_expression() -> u64 { 99 }
///
/// parameter_types! {
///    pub const Argument: u64 = non_const_expression();
/// }
/// ```
#[macro_export]
macro_rules! parameter_types {
	(
		$( #[ $attr:meta ] )*
		$vis:vis const $name:ident $(< $($ty_params:ident),* >)?: $type:ty = $value:expr;
		$( $rest:tt )*
	) => (
		$( #[ $attr ] )*
		$vis struct $name $(
			< $($ty_params),* >( $($crate::sp_std::marker::PhantomData<$ty_params>),* )
		)?;
		$crate::parameter_types!(IMPL_CONST $name , $type , $value $( $(, $ty_params)* )?);
		$crate::parameter_types!( $( $rest )* );
	);
	(
		$( #[ $attr:meta ] )*
		$vis:vis $name:ident $(< $($ty_params:ident),* >)?: $type:ty = $value:expr;
		$( $rest:tt )*
	) => (
		$( #[ $attr ] )*
		$vis struct $name $(
			< $($ty_params),* >( $($crate::sp_std::marker::PhantomData<$ty_params>),* )
		)?;
		$crate::parameter_types!(IMPL $name, $type, $value $( $(, $ty_params)* )?);
		$crate::parameter_types!( $( $rest )* );
	);
	(
		$( #[ $attr:meta ] )*
		$vis:vis storage $name:ident $(< $($ty_params:ident),* >)?: $type:ty = $value:expr;
		$( $rest:tt )*
	) => (
		$( #[ $attr ] )*
		$vis struct $name $(
			< $($ty_params),* >( $($crate::sp_std::marker::PhantomData<$ty_params>),* )
		)?;
		$crate::parameter_types!(IMPL_STORAGE $name, $type, $value $( $(, $ty_params)* )?);
		$crate::parameter_types!( $( $rest )* );
	);
	() => ();
	(IMPL_CONST $name:ident, $type:ty, $value:expr $(, $ty_params:ident)*) => {
		impl< $($ty_params),* > $name< $($ty_params),* > {
			/// Returns the value of this parameter type.
			pub const fn get() -> $type {
				$value
			}
		}

		impl<_I: From<$type> $(, $ty_params)*> $crate::traits::Get<_I> for $name< $($ty_params),* > {
			fn get() -> _I {
				_I::from(Self::get())
			}
		}

		impl< $($ty_params),* > $crate::traits::TypedGet for $name< $($ty_params),* > {
			type Type = $type;
			fn get() -> $type {
				Self::get()
			}
		}
	};
	(IMPL $name:ident, $type:ty, $value:expr $(, $ty_params:ident)*) => {
		impl< $($ty_params),* > $name< $($ty_params),* > {
			/// Returns the value of this parameter type.
			pub fn get() -> $type {
				$value
			}
		}

		impl<_I: From<$type>, $(, $ty_params)*> $crate::traits::Get<_I> for $name< $($ty_params),* > {
			fn get() -> _I {
				_I::from(Self::get())
			}
		}

		impl< $($ty_params),* > $crate::traits::TypedGet for $name< $($ty_params),* > {
			type Type = $type;
			fn get() -> $type {
				Self::get()
			}
		}
	};
	(IMPL_STORAGE $name:ident, $type:ty, $value:expr $(, $ty_params:ident)*) => {
		#[allow(unused)]
		impl< $($ty_params),* > $name< $($ty_params),* > {
			/// Returns the key for this parameter type.
			pub fn key() -> [u8; 16] {
				$crate::sp_core_hashing_proc_macro::twox_128!(b":", $name, b":")
			}

			/// Set the value of this parameter type in the storage.
			///
			/// This needs to be executed in an externalities provided
			/// environment.
			pub fn set(value: &$type) {
				$crate::storage::unhashed::put(&Self::key(), value);
			}

			/// Returns the value of this parameter type.
			///
			/// This needs to be executed in an externalities provided
			/// environment.
			#[allow(unused)]
			pub fn get() -> $type {
				$crate::storage::unhashed::get(&Self::key()).unwrap_or_else(|| $value)
			}
		}

		impl<_I: From<$type> $(, $ty_params)*> $crate::traits::Get<_I> for $name< $($ty_params),* > {
			fn get() -> _I {
				_I::from(Self::get())
			}
		}

		impl< $($ty_params),* > $crate::traits::TypedGet for $name< $($ty_params),* > {
			type Type = $type;
			fn get() -> $type {
				Self::get()
			}
		}
	};
	(
		$( #[ $attr:meta ] )*
		$vis:vis static $name:ident: $type:ty = $value:expr;
		$( $rest:tt )*
	) => (
		$crate::parameter_types_impl_thread_local!(
			$( #[ $attr ] )*
			$vis static $name: $type = $value;
		);
		$crate::parameter_types!( $( $rest )* );
	);
}

#[cfg(not(feature = "std"))]
#[macro_export]
macro_rules! parameter_types_impl_thread_local {
	( $( $any:tt )* ) => {
		compile_error!("static parameter types is only available in std and for testing.");
	};
}

#[cfg(feature = "std")]
#[macro_export]
macro_rules! parameter_types_impl_thread_local {
	(
		$(
			$( #[ $attr:meta ] )*
			$vis:vis static $name:ident: $type:ty = $value:expr;
		)*
	) => {
		$crate::parameter_types_impl_thread_local!(
			IMPL_THREAD_LOCAL $( $vis, $name, $type, $value, )*
		);
		$crate::paste::item! {
			$crate::parameter_types!(
				$(
					$( #[ $attr ] )*
					$vis $name: $type = [<$name:snake:upper>].with(|v| v.borrow().clone());
				)*
			);
			$(
				impl $name {
					/// Set the internal value.
					pub fn set(t: $type) {
						[<$name:snake:upper>].with(|v| *v.borrow_mut() = t);
					}

					/// Mutate the internal value in place.
					#[allow(unused)]
					pub fn mutate<R, F: FnOnce(&mut $type) -> R>(mutate: F) -> R{
						let mut current = Self::get();
						let result = mutate(&mut current);
						Self::set(current);
						result
					}

					/// Get current value and replace with initial value of the parameter type.
					#[allow(unused)]
					pub fn take() -> $type {
						let current = Self::get();
						Self::set($value);
						current
					}
				}
			)*
		}
	};
	(IMPL_THREAD_LOCAL $( $vis:vis, $name:ident, $type:ty, $value:expr, )* ) => {
		$crate::paste::item! {
			thread_local! {
				$(
					pub static [<$name:snake:upper>]: std::cell::RefCell<$type> =
						std::cell::RefCell::new($value);
				)*
			}
		}
	};
}

/// Macro for easily creating a new implementation of both the `Get` and `Contains` traits. Use
/// exactly as with `parameter_types`, only the type must be `Ord`.
#[macro_export]
macro_rules! ord_parameter_types {
	(
		$( #[ $attr:meta ] )*
		$vis:vis const $name:ident: $type:ty = $value:expr;
		$( $rest:tt )*
	) => (
		$( #[ $attr ] )*
		$vis struct $name;
		$crate::parameter_types!{IMPL $name , $type , $value}
		$crate::ord_parameter_types!{IMPL $name , $type , $value}
		$crate::ord_parameter_types!{ $( $rest )* }
	);
	() => ();
	(IMPL $name:ident , $type:ty , $value:expr) => {
		impl $crate::traits::SortedMembers<$type> for $name {
			fn contains(t: &$type) -> bool { &$value == t }
			fn sorted_members() -> $crate::sp_std::prelude::Vec<$type> { vec![$value] }
			fn count() -> usize { 1 }
			#[cfg(feature = "runtime-benchmarks")]
			fn add(_: &$type) {}
		}
		impl $crate::traits::Contains<$type> for $name {
			fn contains(t: &$type) -> bool { &$value == t }
		}
	}
}

/// Print out a formatted message.
///
/// # Example
///
/// ```
/// frame_support::runtime_print!("my value is {}", 3);
/// ```
#[macro_export]
macro_rules! runtime_print {
	($($arg:tt)+) => {
		{
			use core::fmt::Write;
			let mut w = $crate::sp_std::Writer::default();
			let _ = core::write!(&mut w, $($arg)+);
			$crate::sp_io::misc::print_utf8(&w.inner())
		}
	}
}

/// Print out the debuggable type.
pub fn debug(data: &impl sp_std::fmt::Debug) {
	runtime_print!("{:?}", data);
}

#[doc(inline)]
pub use frame_support_procedural::{
	construct_runtime, decl_storage, match_and_insert, transactional, PalletError,
	RuntimeDebugNoBound,
};

#[doc(hidden)]
pub use frame_support_procedural::{__create_tt_macro, __generate_dummy_part_checker};

/// Derive [`Clone`] but do not bound any generic.
///
/// This is useful for type generic over runtime:
/// ```
/// # use frame_support::CloneNoBound;
/// trait Config {
/// 		type C: Clone;
/// }
///
/// // Foo implements [`Clone`] because `C` bounds [`Clone`].
/// // Otherwise compilation will fail with an output telling `c` doesn't implement [`Clone`].
/// #[derive(CloneNoBound)]
/// struct Foo<T: Config> {
/// 		c: T::C,
/// }
/// ```
pub use frame_support_procedural::CloneNoBound;

/// Derive [`Eq`] but do not bound any generic.
///
/// This is useful for type generic over runtime:
/// ```
/// # use frame_support::{EqNoBound, PartialEqNoBound};
/// trait Config {
/// 		type C: Eq;
/// }
///
/// // Foo implements [`Eq`] because `C` bounds [`Eq`].
/// // Otherwise compilation will fail with an output telling `c` doesn't implement [`Eq`].
/// #[derive(PartialEqNoBound, EqNoBound)]
/// struct Foo<T: Config> {
/// 		c: T::C,
/// }
/// ```
pub use frame_support_procedural::EqNoBound;

/// Derive [`PartialEq`] but do not bound any generic.
///
/// This is useful for type generic over runtime:
/// ```
/// # use frame_support::PartialEqNoBound;
/// trait Config {
/// 		type C: PartialEq;
/// }
///
/// // Foo implements [`PartialEq`] because `C` bounds [`PartialEq`].
/// // Otherwise compilation will fail with an output telling `c` doesn't implement [`PartialEq`].
/// #[derive(PartialEqNoBound)]
/// struct Foo<T: Config> {
/// 		c: T::C,
/// }
/// ```
pub use frame_support_procedural::PartialEqNoBound;

/// Derive [`Debug`] but do not bound any generic.
///
/// This is useful for type generic over runtime:
/// ```
/// # use frame_support::DebugNoBound;
/// # use core::fmt::Debug;
/// trait Config {
/// 		type C: Debug;
/// }
///
/// // Foo implements [`Debug`] because `C` bounds [`Debug`].
/// // Otherwise compilation will fail with an output telling `c` doesn't implement [`Debug`].
/// #[derive(DebugNoBound)]
/// struct Foo<T: Config> {
/// 		c: T::C,
/// }
/// ```
pub use frame_support_procedural::DebugNoBound;

/// Derive [`Default`] but do not bound any generic.
///
/// This is useful for type generic over runtime:
/// ```
/// # use frame_support::DefaultNoBound;
/// # use core::default::Default;
/// trait Config {
/// 	type C: Default;
/// }
///
/// // Foo implements [`Default`] because `C` bounds [`Default`].
/// // Otherwise compilation will fail with an output telling `c` doesn't implement [`Default`].
/// #[derive(DefaultNoBound)]
/// struct Foo<T: Config> {
/// 	c: T::C,
/// }
///
/// // Also works with enums, by specifying the default with #[default]:
/// #[derive(DefaultNoBound)]
/// enum Bar<T: Config> {
/// 	// Bar will implement Default as long as all of the types within Baz also implement default.
/// 	#[default]
/// 	Baz(T::C),
/// 	Quxx,
/// }
/// ```
pub use frame_support_procedural::DefaultNoBound;

/// Assert the annotated function is executed within a storage transaction.
///
/// The assertion is enabled for native execution and when `debug_assertions` are enabled.
///
/// # Example
///
/// ```
/// # use frame_support::{
/// # 	require_transactional, transactional, dispatch::DispatchResult
/// # };
///
/// #[require_transactional]
/// fn update_all(value: u32) -> DispatchResult {
/// 	// Update multiple storages.
/// 	// Return `Err` to indicate should revert.
/// 	Ok(())
/// }
///
/// #[transactional]
/// fn safe_update(value: u32) -> DispatchResult {
/// 	// This is safe
/// 	update_all(value)
/// }
///
/// fn unsafe_update(value: u32) -> DispatchResult {
/// 	// this may panic if unsafe_update is not called within a storage transaction
/// 	update_all(value)
/// }
/// ```
pub use frame_support_procedural::require_transactional;

/// Convert the current crate version into a [`CrateVersion`](crate::traits::CrateVersion).
///
/// It uses the `CARGO_PKG_VERSION_MAJOR`, `CARGO_PKG_VERSION_MINOR` and
/// `CARGO_PKG_VERSION_PATCH` environment variables to fetch the crate version.
/// This means that the [`CrateVersion`](crate::traits::CrateVersion)
/// object will correspond to the version of the crate the macro is called in!
///
/// # Example
///
/// ```
/// # use frame_support::{traits::CrateVersion, crate_to_crate_version};
/// const Version: CrateVersion = crate_to_crate_version!();
/// ```
pub use frame_support_procedural::crate_to_crate_version;

/// Return Err of the expression: `return Err($expression);`.
///
/// Used as `fail!(expression)`.
#[macro_export]
macro_rules! fail {
	( $y:expr ) => {{
		return Err($y.into())
	}};
}

/// Evaluate `$x:expr` and if not true return `Err($y:expr)`.
///
/// Used as `ensure!(expression_to_ensure, expression_to_return_on_false)`.
#[macro_export]
macro_rules! ensure {
	( $x:expr, $y:expr $(,)? ) => {{
		if !$x {
			$crate::fail!($y);
		}
	}};
}

/// Evaluate an expression, assert it returns an expected `Err` value and that
/// runtime storage has not been mutated (i.e. expression is a no-operation).
///
/// Used as `assert_noop(expression_to_assert, expected_error_expression)`.
#[macro_export]
macro_rules! assert_noop {
	(
		$x:expr,
		$y:expr $(,)?
	) => {
		let h = $crate::storage_root($crate::StateVersion::V1);
		$crate::assert_err!($x, $y);
		assert_eq!(h, $crate::storage_root($crate::StateVersion::V1), "storage has been mutated");
	};
}

/// Evaluate any expression and assert that runtime storage has not been mutated
/// (i.e. expression is a storage no-operation).
///
/// Used as `assert_storage_noop(expression_to_assert)`.
#[macro_export]
macro_rules! assert_storage_noop {
	(
		$x:expr
	) => {
		let h = $crate::storage_root($crate::StateVersion::V1);
		$x;
		assert_eq!(h, $crate::storage_root($crate::StateVersion::V1));
	};
}

/// Assert an expression returns an error specified.
///
/// Used as `assert_err!(expression_to_assert, expected_error_expression)`
#[macro_export]
macro_rules! assert_err {
	( $x:expr , $y:expr $(,)? ) => {
		assert_eq!($x, Err($y.into()));
	};
}

/// Assert an expression returns an error specified.
///
/// This can be used on `DispatchResultWithPostInfo` when the post info should
/// be ignored.
#[macro_export]
macro_rules! assert_err_ignore_postinfo {
	( $x:expr , $y:expr $(,)? ) => {
		$crate::assert_err!($x.map(|_| ()).map_err(|e| e.error), $y);
	};
}

/// Assert an expression returns error with the given weight.
#[macro_export]
macro_rules! assert_err_with_weight {
	($call:expr, $err:expr, $weight:expr $(,)? ) => {
		if let Err(dispatch_err_with_post) = $call {
			$crate::assert_err!($call.map(|_| ()).map_err(|e| e.error), $err);
			assert_eq!(dispatch_err_with_post.post_info.actual_weight, $weight);
		} else {
			panic!("expected Err(_), got Ok(_).")
		}
	};
}

/// Panic if an expression doesn't evaluate to `Ok`.
///
/// Used as `assert_ok!(expression_to_assert, expected_ok_expression)`,
/// or `assert_ok!(expression_to_assert)` which would assert against `Ok(())`.
#[macro_export]
macro_rules! assert_ok {
	( $x:expr $(,)? ) => {
		let is = $x;
		match is {
			Ok(_) => (),
			_ => assert!(false, "Expected Ok(_). Got {:#?}", is),
		}
	};
	( $x:expr, $y:expr $(,)? ) => {
		assert_eq!($x, Ok($y));
	};
}

/// Assert that the maximum encoding size does not exceed the value defined in
/// [`MAX_MODULE_ERROR_ENCODED_SIZE`] during compilation.
///
/// This macro is intended to be used in conjunction with `tt_call!`.
#[macro_export]
macro_rules! assert_error_encoded_size {
	{
		path = [{ $($path:ident)::+ }]
		runtime = [{ $runtime:ident }]
		assert_message = [{ $assert_message:literal }]
		error = [{ $error:ident }]
	} => {
		const _: () = assert!(
			<
				$($path::)+$error<$runtime> as $crate::traits::PalletError
			>::MAX_ENCODED_SIZE <= $crate::MAX_MODULE_ERROR_ENCODED_SIZE,
			$assert_message
		);
	};
	{
		path = [{ $($path:ident)::+ }]
		runtime = [{ $runtime:ident }]
		assert_message = [{ $assert_message:literal }]
	} => {};
}

#[cfg(feature = "std")]
#[doc(hidden)]
pub use serde::{Deserialize, Serialize};

#[cfg(test)]
pub mod tests {
	use super::*;
	use crate::metadata::{
		PalletStorageMetadata, StorageEntryMetadata, StorageEntryModifier, StorageEntryType,
		StorageHasher,
	};
	use codec::{Codec, EncodeLike};
	use frame_support::traits::CrateVersion;
	use sp_io::{MultiRemovalResults, TestExternalities};
	use sp_std::result;

	/// A PalletInfo implementation which just panics.
	pub struct PanicPalletInfo;

	impl crate::traits::PalletInfo for PanicPalletInfo {
		fn index<P: 'static>() -> Option<usize> {
			unimplemented!("PanicPalletInfo mustn't be triggered by tests");
		}
		fn name<P: 'static>() -> Option<&'static str> {
			unimplemented!("PanicPalletInfo mustn't be triggered by tests");
		}
		fn module_name<P: 'static>() -> Option<&'static str> {
			unimplemented!("PanicPalletInfo mustn't be triggered by tests");
		}
		fn crate_version<P: 'static>() -> Option<CrateVersion> {
			unimplemented!("PanicPalletInfo mustn't be triggered by tests");
		}
	}

	pub trait Config: 'static {
		type BlockNumber: Codec + EncodeLike + Default + TypeInfo;
		type RuntimeOrigin;
		type PalletInfo: crate::traits::PalletInfo;
		type DbWeight: crate::traits::Get<crate::weights::RuntimeDbWeight>;
	}

	mod module {
		#![allow(dead_code)]

		use super::Config;

		decl_module! {
			pub struct Module<T: Config> for enum Call where origin: T::RuntimeOrigin, system=self  {}
		}
	}

	use self::module::Module;

	decl_storage! {
		trait Store for Module<T: Config> as Test {
			pub Data get(fn data) build(|_| vec![(15u32, 42u64)]):
				map hasher(twox_64_concat) u32 => u64;
			pub OptionLinkedMap: map hasher(blake2_128_concat) u32 => Option<u32>;
			pub GenericData get(fn generic_data):
				map hasher(identity) T::BlockNumber => T::BlockNumber;
			pub GenericData2 get(fn generic_data2):
				map hasher(blake2_128_concat) T::BlockNumber => Option<T::BlockNumber>;
			pub DataDM config(test_config) build(|_| vec![(15u32, 16u32, 42u64)]):
				double_map hasher(twox_64_concat) u32, hasher(blake2_128_concat) u32 => u64;
			pub GenericDataDM:
				double_map hasher(blake2_128_concat) T::BlockNumber, hasher(identity) T::BlockNumber
				=> T::BlockNumber;
			pub GenericData2DM:
				double_map hasher(blake2_128_concat) T::BlockNumber, hasher(twox_64_concat) T::BlockNumber
				=> Option<T::BlockNumber>;
			pub AppendableDM:
				double_map hasher(blake2_128_concat) u32, hasher(blake2_128_concat) T::BlockNumber => Vec<u32>;
		}
	}

	struct Test;

	impl Config for Test {
		type BlockNumber = u32;
		type RuntimeOrigin = u32;
		type PalletInfo = PanicPalletInfo;
		type DbWeight = ();
	}

	fn new_test_ext() -> TestExternalities {
		GenesisConfig::default().build_storage().unwrap().into()
	}

	type Map = Data;

	trait Sorted {
		fn sorted(self) -> Self;
	}

	impl<T: Ord> Sorted for Vec<T> {
		fn sorted(mut self) -> Self {
			self.sort();
			self
		}
	}

	#[test]
	fn storage_alias_works() {
		new_test_ext().execute_with(|| {
			#[crate::storage_alias]
			type GenericData2<T> = StorageMap<
				Test,
				Blake2_128Concat,
				<T as Config>::BlockNumber,
				<T as Config>::BlockNumber,
			>;

			assert_eq!(Module::<Test>::generic_data2(5), None);
			GenericData2::<Test>::insert(5, 5);
			assert_eq!(Module::<Test>::generic_data2(5), Some(5));

			/// Some random docs that ensure that docs are accepted
			#[crate::storage_alias]
			pub type GenericData<T> = StorageMap<
				Test2,
				Blake2_128Concat,
				<T as Config>::BlockNumber,
				<T as Config>::BlockNumber,
			>;
		});
	}

	#[test]
	fn map_issue_3318() {
		new_test_ext().execute_with(|| {
			OptionLinkedMap::insert(1, 1);
			assert_eq!(OptionLinkedMap::get(1), Some(1));
			OptionLinkedMap::insert(1, 2);
			assert_eq!(OptionLinkedMap::get(1), Some(2));
		});
	}

	#[test]
	fn map_swap_works() {
		new_test_ext().execute_with(|| {
			OptionLinkedMap::insert(0, 0);
			OptionLinkedMap::insert(1, 1);
			OptionLinkedMap::insert(2, 2);
			OptionLinkedMap::insert(3, 3);

			let collect = || OptionLinkedMap::iter().collect::<Vec<_>>().sorted();
			assert_eq!(collect(), vec![(0, 0), (1, 1), (2, 2), (3, 3)]);

			// Two existing
			OptionLinkedMap::swap(1, 2);
			assert_eq!(collect(), vec![(0, 0), (1, 2), (2, 1), (3, 3)]);

			// Back to normal
			OptionLinkedMap::swap(2, 1);
			assert_eq!(collect(), vec![(0, 0), (1, 1), (2, 2), (3, 3)]);

			// Left existing
			OptionLinkedMap::swap(2, 5);
			assert_eq!(collect(), vec![(0, 0), (1, 1), (3, 3), (5, 2)]);

			// Right existing
			OptionLinkedMap::swap(5, 2);
			assert_eq!(collect(), vec![(0, 0), (1, 1), (2, 2), (3, 3)]);
		});
	}

	#[test]
	fn double_map_swap_works() {
		new_test_ext().execute_with(|| {
			DataDM::insert(0, 1, 1);
			DataDM::insert(1, 0, 2);
			DataDM::insert(1, 1, 3);

			let get_all = || {
				vec![
					DataDM::get(0, 1),
					DataDM::get(1, 0),
					DataDM::get(1, 1),
					DataDM::get(2, 0),
					DataDM::get(2, 1),
				]
			};
			assert_eq!(get_all(), vec![1, 2, 3, 0, 0]);

			// Two existing
			DataDM::swap(0, 1, 1, 0);
			assert_eq!(get_all(), vec![2, 1, 3, 0, 0]);

			// Left existing
			DataDM::swap(1, 0, 2, 0);
			assert_eq!(get_all(), vec![2, 0, 3, 1, 0]);

			// Right existing
			DataDM::swap(2, 1, 1, 1);
			assert_eq!(get_all(), vec![2, 0, 0, 1, 3]);
		});
	}

	#[test]
	fn map_basic_insert_remove_should_work() {
		new_test_ext().execute_with(|| {
			// initialized during genesis
			assert_eq!(Map::get(&15u32), 42u64);

			// get / insert / take
			let key = 17u32;
			assert_eq!(Map::get(&key), 0u64);
			Map::insert(key, 4u64);
			assert_eq!(Map::get(&key), 4u64);
			assert_eq!(Map::take(&key), 4u64);
			assert_eq!(Map::get(&key), 0u64);

			// mutate
			Map::mutate(&key, |val| {
				*val = 15;
			});
			assert_eq!(Map::get(&key), 15u64);

			// remove
			Map::remove(&key);
			assert_eq!(Map::get(&key), 0u64);
		});
	}

	#[test]
	fn map_iteration_should_work() {
		new_test_ext().execute_with(|| {
			assert_eq!(Map::iter().collect::<Vec<_>>().sorted(), vec![(15, 42)]);
			// insert / remove
			let key = 17u32;
			Map::insert(key, 4u64);
			assert_eq!(Map::iter().collect::<Vec<_>>().sorted(), vec![(15, 42), (key, 4)]);
			assert_eq!(Map::take(&15), 42u64);
			assert_eq!(Map::take(&key), 4u64);
			assert_eq!(Map::iter().collect::<Vec<_>>().sorted(), vec![]);

			// Add couple of more elements
			Map::insert(key, 42u64);
			assert_eq!(Map::iter().collect::<Vec<_>>().sorted(), vec![(key, 42)]);
			Map::insert(key + 1, 43u64);
			assert_eq!(Map::iter().collect::<Vec<_>>().sorted(), vec![(key, 42), (key + 1, 43)]);

			// mutate
			let key = key + 2;
			Map::mutate(&key, |val| {
				*val = 15;
			});
			assert_eq!(
				Map::iter().collect::<Vec<_>>().sorted(),
				vec![(key - 2, 42), (key - 1, 43), (key, 15)]
			);
			Map::mutate(&key, |val| {
				*val = 17;
			});
			assert_eq!(
				Map::iter().collect::<Vec<_>>().sorted(),
				vec![(key - 2, 42), (key - 1, 43), (key, 17)]
			);

			// remove first
			Map::remove(&key);
			assert_eq!(
				Map::iter().collect::<Vec<_>>().sorted(),
				vec![(key - 2, 42), (key - 1, 43)]
			);

			// remove last from the list
			Map::remove(&(key - 2));
			assert_eq!(Map::iter().collect::<Vec<_>>().sorted(), vec![(key - 1, 43)]);

			// remove the last element
			Map::remove(&(key - 1));
			assert_eq!(Map::iter().collect::<Vec<_>>().sorted(), vec![]);
		});
	}

	#[test]
	fn double_map_basic_insert_remove_remove_prefix_with_commit_should_work() {
		let key1 = 17u32;
		let key2 = 18u32;
		type DoubleMap = DataDM;
		let mut e = new_test_ext();
		e.execute_with(|| {
			// initialized during genesis
			assert_eq!(DoubleMap::get(&15u32, &16u32), 42u64);

			// get / insert / take
			assert_eq!(DoubleMap::get(&key1, &key2), 0u64);
			DoubleMap::insert(&key1, &key2, &4u64);
			assert_eq!(DoubleMap::get(&key1, &key2), 4u64);
			assert_eq!(DoubleMap::take(&key1, &key2), 4u64);
			assert_eq!(DoubleMap::get(&key1, &key2), 0u64);

			// mutate
			DoubleMap::mutate(&key1, &key2, |val| *val = 15);
			assert_eq!(DoubleMap::get(&key1, &key2), 15u64);

			// remove
			DoubleMap::remove(&key1, &key2);
			assert_eq!(DoubleMap::get(&key1, &key2), 0u64);

			// remove prefix
			DoubleMap::insert(&key1, &key2, &4u64);
			DoubleMap::insert(&key1, &(key2 + 1), &4u64);
			DoubleMap::insert(&(key1 + 1), &key2, &4u64);
			DoubleMap::insert(&(key1 + 1), &(key2 + 1), &4u64);
		});
		e.commit_all().unwrap();
		e.execute_with(|| {
			assert!(matches!(
				DoubleMap::clear_prefix(&key1, u32::max_value(), None),
				MultiRemovalResults { maybe_cursor: None, backend: 2, unique: 2, loops: 2 }
			));
			assert_eq!(DoubleMap::get(&key1, &key2), 0u64);
			assert_eq!(DoubleMap::get(&key1, &(key2 + 1)), 0u64);
			assert_eq!(DoubleMap::get(&(key1 + 1), &key2), 4u64);
			assert_eq!(DoubleMap::get(&(key1 + 1), &(key2 + 1)), 4u64);
		});
	}

	#[test]
	fn double_map_basic_insert_remove_remove_prefix_should_work() {
		new_test_ext().execute_with(|| {
			let key1 = 17u32;
			let key2 = 18u32;
			type DoubleMap = DataDM;

			// initialized during genesis
			assert_eq!(DoubleMap::get(&15u32, &16u32), 42u64);

			// get / insert / take
			assert_eq!(DoubleMap::get(&key1, &key2), 0u64);
			DoubleMap::insert(&key1, &key2, &4u64);
			assert_eq!(DoubleMap::get(&key1, &key2), 4u64);
			assert_eq!(DoubleMap::take(&key1, &key2), 4u64);
			assert_eq!(DoubleMap::get(&key1, &key2), 0u64);

			// mutate
			DoubleMap::mutate(&key1, &key2, |val| *val = 15);
			assert_eq!(DoubleMap::get(&key1, &key2), 15u64);

			// remove
			DoubleMap::remove(&key1, &key2);
			assert_eq!(DoubleMap::get(&key1, &key2), 0u64);

			// remove prefix
			DoubleMap::insert(&key1, &key2, &4u64);
			DoubleMap::insert(&key1, &(key2 + 1), &4u64);
			DoubleMap::insert(&(key1 + 1), &key2, &4u64);
			DoubleMap::insert(&(key1 + 1), &(key2 + 1), &4u64);
			// all in overlay
			assert!(matches!(
				DoubleMap::clear_prefix(&key1, u32::max_value(), None),
				MultiRemovalResults { maybe_cursor: None, backend: 0, unique: 0, loops: 0 }
			));
			// Note this is the incorrect answer (for now), since we are using v2 of
			// `clear_prefix`.
			// When we switch to v3, then this will become:
			//   MultiRemovalResults:: { maybe_cursor: None, backend: 0, unique: 2, loops: 2 },
			assert!(matches!(
				DoubleMap::clear_prefix(&key1, u32::max_value(), None),
				MultiRemovalResults { maybe_cursor: None, backend: 0, unique: 0, loops: 0 }
			));
			assert_eq!(DoubleMap::get(&key1, &key2), 0u64);
			assert_eq!(DoubleMap::get(&key1, &(key2 + 1)), 0u64);
			assert_eq!(DoubleMap::get(&(key1 + 1), &key2), 4u64);
			assert_eq!(DoubleMap::get(&(key1 + 1), &(key2 + 1)), 4u64);
		});
	}

	#[test]
	fn double_map_append_should_work() {
		new_test_ext().execute_with(|| {
			type DoubleMap = AppendableDM<Test>;

			let key1 = 17u32;
			let key2 = 18u32;

			DoubleMap::insert(&key1, &key2, &vec![1]);
			DoubleMap::append(&key1, &key2, 2);
			assert_eq!(DoubleMap::get(&key1, &key2), &[1, 2]);
		});
	}

	#[test]
	fn double_map_mutate_exists_should_work() {
		new_test_ext().execute_with(|| {
			type DoubleMap = DataDM;

			let (key1, key2) = (11, 13);

			// mutated
			DoubleMap::mutate_exists(key1, key2, |v| *v = Some(1));
			assert_eq!(DoubleMap::get(&key1, key2), 1);

			// removed if mutated to `None`
			DoubleMap::mutate_exists(key1, key2, |v| *v = None);
			assert!(!DoubleMap::contains_key(&key1, key2));
		});
	}

	#[test]
	fn double_map_try_mutate_exists_should_work() {
		new_test_ext().execute_with(|| {
			type DoubleMap = DataDM;
			type TestResult = result::Result<(), &'static str>;

			let (key1, key2) = (11, 13);

			// mutated if `Ok`
			assert_ok!(DoubleMap::try_mutate_exists(key1, key2, |v| -> TestResult {
				*v = Some(1);
				Ok(())
			}));
			assert_eq!(DoubleMap::get(&key1, key2), 1);

			// no-op if `Err`
			assert_noop!(
				DoubleMap::try_mutate_exists(key1, key2, |v| -> TestResult {
					*v = Some(2);
					Err("nah")
				}),
				"nah"
			);

			// removed if mutated to`None`
			assert_ok!(DoubleMap::try_mutate_exists(key1, key2, |v| -> TestResult {
				*v = None;
				Ok(())
			}));
			assert!(!DoubleMap::contains_key(&key1, key2));
		});
	}

	fn expected_metadata() -> PalletStorageMetadata {
		PalletStorageMetadata {
			prefix: "Test",
			entries: vec![
				StorageEntryMetadata {
					name: "Data",
					modifier: StorageEntryModifier::Default,
					ty: StorageEntryType::Map {
						hashers: vec![StorageHasher::Twox64Concat],
						key: scale_info::meta_type::<u32>(),
						value: scale_info::meta_type::<u64>(),
					},
					default: vec![0, 0, 0, 0, 0, 0, 0, 0],
					docs: vec![],
				},
				StorageEntryMetadata {
					name: "OptionLinkedMap",
					modifier: StorageEntryModifier::Optional,
					ty: StorageEntryType::Map {
						hashers: vec![StorageHasher::Blake2_128Concat],
						key: scale_info::meta_type::<u32>(),
						value: scale_info::meta_type::<u32>(),
					},
					default: vec![0],
					docs: vec![],
				},
				StorageEntryMetadata {
					name: "GenericData",
					modifier: StorageEntryModifier::Default,
					ty: StorageEntryType::Map {
						hashers: vec![StorageHasher::Identity],
						key: scale_info::meta_type::<u32>(),
						value: scale_info::meta_type::<u32>(),
					},
					default: vec![0, 0, 0, 0],
					docs: vec![],
				},
				StorageEntryMetadata {
					name: "GenericData2",
					modifier: StorageEntryModifier::Optional,
					ty: StorageEntryType::Map {
						hashers: vec![StorageHasher::Blake2_128Concat],
						key: scale_info::meta_type::<u32>(),
						value: scale_info::meta_type::<u32>(),
					},
					default: vec![0],
					docs: vec![],
				},
				StorageEntryMetadata {
					name: "DataDM",
					modifier: StorageEntryModifier::Default,
					ty: StorageEntryType::Map {
						hashers: vec![StorageHasher::Twox64Concat, StorageHasher::Blake2_128Concat],
						key: scale_info::meta_type::<(u32, u32)>(),
						value: scale_info::meta_type::<u64>(),
					},
					default: vec![0, 0, 0, 0, 0, 0, 0, 0],
					docs: vec![],
				},
				StorageEntryMetadata {
					name: "GenericDataDM",
					modifier: StorageEntryModifier::Default,
					ty: StorageEntryType::Map {
						hashers: vec![StorageHasher::Blake2_128Concat, StorageHasher::Identity],
						key: scale_info::meta_type::<(u32, u32)>(),
						value: scale_info::meta_type::<u32>(),
					},
					default: vec![0, 0, 0, 0],
					docs: vec![],
				},
				StorageEntryMetadata {
					name: "GenericData2DM",
					modifier: StorageEntryModifier::Optional,
					ty: StorageEntryType::Map {
						hashers: vec![StorageHasher::Blake2_128Concat, StorageHasher::Twox64Concat],
						key: scale_info::meta_type::<(u32, u32)>(),
						value: scale_info::meta_type::<u32>(),
					},
					default: vec![0],
					docs: vec![],
				},
				StorageEntryMetadata {
					name: "AppendableDM",
					modifier: StorageEntryModifier::Default,
					ty: StorageEntryType::Map {
						hashers: vec![
							StorageHasher::Blake2_128Concat,
							StorageHasher::Blake2_128Concat,
						],
						key: scale_info::meta_type::<(u32, u32)>(),
						value: scale_info::meta_type::<Vec<u32>>(),
					},
					default: vec![0],
					docs: vec![],
				},
			],
		}
	}

	#[test]
	fn store_metadata() {
		let metadata = Module::<Test>::storage_metadata();
		pretty_assertions::assert_eq!(expected_metadata(), metadata);
	}

	parameter_types! {
		storage StorageParameter: u64 = 10;
	}

	#[test]
	fn check_storage_parameter_type_works() {
		TestExternalities::default().execute_with(|| {
			assert_eq!(sp_io::hashing::twox_128(b":StorageParameter:"), StorageParameter::key());

			assert_eq!(10, StorageParameter::get());

			StorageParameter::set(&300);
			assert_eq!(300, StorageParameter::get());
		})
	}

	parameter_types! {
		pub const BlockHashCount: u64 = 250;
		pub static Members: Vec<u64> = vec![];
		pub const Foo: Option<u64> = None;
	}
}

/// Prelude to be used alongside pallet macro, for ease of use.
pub mod pallet_prelude {
	#[cfg(feature = "std")]
	pub use crate::traits::GenesisBuild;
	pub use crate::{
		dispatch::{
			DispatchClass, DispatchError, DispatchResult, DispatchResultWithPostInfo, Parameter,
			Pays,
		},
		ensure,
		inherent::{InherentData, InherentIdentifier, ProvideInherent},
		storage,
		storage::{
			bounded_vec::BoundedVec,
			types::{
				CountedStorageMap, Key as NMapKey, OptionQuery, ResultQuery, StorageDoubleMap,
				StorageMap, StorageNMap, StorageValue, ValueQuery,
			},
		},
		traits::{
			ConstU32, EnsureOrigin, Get, GetDefault, GetStorageVersion, Hooks, IsType,
			PalletInfoAccess, StorageInfoTrait, StorageVersion, TypedGet,
		},
		Blake2_128, Blake2_128Concat, Blake2_256, CloneNoBound, DebugNoBound, EqNoBound, Identity,
		PartialEqNoBound, RuntimeDebug, RuntimeDebugNoBound, Twox128, Twox256, Twox64Concat,
	};
	pub use codec::{Decode, Encode, MaxEncodedLen};
	pub use frame_support::pallet_macros::*;
	pub use scale_info::TypeInfo;
	pub use sp_runtime::{
		traits::{MaybeSerializeDeserialize, Member, ValidateUnsigned},
		transaction_validity::{
			InvalidTransaction, TransactionLongevity, TransactionPriority, TransactionSource,
			TransactionTag, TransactionValidity, TransactionValidityError, UnknownTransaction,
			ValidTransaction,
		},
		MAX_MODULE_ERROR_ENCODED_SIZE,
	};
	pub use sp_std::marker::PhantomData;
	pub use sp_weights::Weight;
}

/// The `pallet` attribute macro defines a pallet that can be used with
/// [`construct_runtime!`]. It must be attached to a module named `pallet` as follows:
///
/// ```ignore
/// #[pallet]
/// pub mod pallet {
/// 	...
/// }
/// ```
///
/// Note that various types can be automatically imported using
/// [`frame_support::pallet_prelude`] and `frame_system::pallet_prelude`:
///
/// ```ignore
/// #[pallet]
/// pub mod pallet {
/// 	use frame_support::pallet_prelude::*;
/// 	use frame_system::pallet_prelude::*;
/// 	...
/// }
/// ```
///
/// # pallet::* Attributes
///
/// The `pallet` macro will parse any items within your `pallet` module that are annotated with
/// `#[pallet::*]` attributes. Some of these attributes are mandatory and some are optional,
/// and they can attach to different types of items within your pallet depending on the
/// attribute in question. The full list of `#[pallet::*]` attributes is shown below in the
/// order in which they are mentioned in this document:
///
/// * [`pallet::pallet`](#pallet-struct-placeholder-palletpallet-mandatory)
/// * [`pallet::config`](#config-trait-palletconfig-mandatory)
/// * [`pallet::constant`](#palletconstant)
/// * [`pallet::disable_frame_system_supertrait_check`](#disable_supertrait_check)
/// * [`pallet::generate_store($vis trait Store)`](#palletgenerate_storevis-trait-store)
/// * [`pallet::generate_storage_info`](#palletgenerate_storage_info)
/// * [`pallet::storage_version`](#palletstorage_version)
/// * [`pallet::hooks`](#hooks-pallethooks-optional)
/// * [`pallet::call`](#call-palletcall-optional)
/// * [`pallet::weight($expr)`](#palletweightexpr)
/// * [`pallet::compact`](#palletcompact-some_arg-some_type)
/// * [`pallet::call_index($idx)`](#palletcall_indexidx)
/// * [`pallet::extra_constants`](#extra-constants-palletextra_constants-optional)
/// * [`pallet::error`](#error-palleterror-optional)
/// * [`pallet::event`](#event-palletevent-optional)
/// * [`pallet::generate_deposit($visibility fn
///   deposit_event)`](#palletgenerate_depositvisibility-fn-deposit_event)
/// * [`pallet::storage`](#storage-palletstorage-optional)
/// * [`pallet::getter(fn $my_getter_fn_name)`](#palletgetterfn-my_getter_fn_name-optional)
/// * [`pallet::storage_prefix = "SomeName"`](#palletstorage_prefix--somename-optional)
/// * [`pallet::unbounded`](#palletunbounded-optional)
/// * [`pallet::whitelist_storage`](#palletwhitelist_storage-optional)
/// * [`cfg(..)`](#cfg-for-storage) (on storage items)
/// * [`pallet::type_value`](#type-value-pallettype_value-optional)
/// * [`pallet::genesis_config`](#genesis-config-palletgenesis_config-optional)
/// * [`pallet::genesis_build`](#genesis-build-palletgenesis_build-optional)
/// * [`pallet::inherent`](#inherent-palletinherent-optional)
/// * [`pallet::validate_unsigned`](#validate-unsigned-palletvalidate_unsigned-optional)
/// * [`pallet::origin`](#origin-palletorigin-optional)
///
/// Note that at compile-time, the `#[pallet]` macro will analyze and expand all of these
/// attributes, ultimately removing their AST nodes before they can be parsed as real
/// attribute macro calls. This means that technically we do not need attribute macro
/// definitions for any of these attributes, however, for consistency and discoverability
/// reasons, we still maintain stub attribute macro definitions for all of these attributes in
/// the [`pallet_macros`] module which is automatically included in all pallets as part of the
/// pallet prelude. The actual "work" for all of these attribute macros can be found in the
/// macro expansion for `#[pallet]`.
///
/// Also note that in this document, pallet attributes are explained using the syntax of
/// non-instantiable pallets. For an example of an instantiable pallet, see [this
/// example](#example-of-an-instantiable-pallet).
///
/// # Dev Mode (`#[pallet(dev_mode)]`)
///
/// Specifying the argument `dev_mode` on the `#[pallet]` or `#[frame_support::pallet]`
/// attribute attached to your pallet module will allow you to enable dev mode for a pallet.
/// The aim of dev mode is to loosen some of the restrictions and requirements placed on
/// production pallets for easy tinkering and development. Dev mode pallets should not be used
/// in production. Enabling dev mode has the following effects:
///
/// * Weights no longer need to be specified on every `#[pallet::call]` declaration. By
///   default, dev mode pallets will assume a weight of zero (`0`) if a weight is not
///   specified. This is equivalent to specifying `#[weight(0)]` on all calls that do not
///   specify a weight.
/// * All storages are marked as unbounded, meaning you do not need to implement
///   `MaxEncodedLen` on storage types. This is equivalent to specifying `#[pallet::unbounded]`
///   on all storage type definitions.
///
/// Note that the `dev_mode` argument can only be supplied to the `#[pallet]` or
/// `#[frame_support::pallet]` attribute macro that encloses your pallet module. This argument
/// cannot be specified anywhere else, including but not limited to the `#[pallet::pallet]`
/// attribute macro.
///
/// <div class="example-wrap" style="display:inline-block"><pre class="compile_fail"
/// style="white-space:normal;font:inherit;">
/// <strong>WARNING</strong>:
/// You should not deploy or use dev mode pallets in production. Doing so can break your chain
/// and therefore should never be done. Once you are done tinkering, you should remove the
/// 'dev_mode' argument from your #[pallet] declaration and fix any compile errors before
/// attempting to use your pallet in a production scenario.
/// </pre></div>
///
/// # Pallet struct placeholder: `#[pallet::pallet]` (mandatory)
///
/// The pallet struct placeholder `#[pallet::pallet]` is mandatory and allows you to specify
/// pallet information.
///
/// The struct must be defined as follows:
/// ```ignore
/// #[pallet::pallet]
/// pub struct Pallet<T>(_);
/// ```
/// I.e. a regular struct definition named `Pallet`, with generic T and no where clause.
///
/// ## Macro expansion:
///
/// The macro adds this attribute to the struct definition:
/// ```ignore
/// #[derive(
/// 	frame_support::CloneNoBound,
/// 	frame_support::EqNoBound,
/// 	frame_support::PartialEqNoBound,
/// 	frame_support::RuntimeDebugNoBound,
/// )]
/// ```
/// and replaces the type `_` with `PhantomData<T>`. It also implements on the pallet:
/// * [`GetStorageVersion`](`traits::GetStorageVersion`)
/// * [`OnGenesis`](`traits::OnGenesis`): contains some logic to write the pallet version into
///   storage.
/// * `PalletErrorTypeInfo`: provides the type information for the pallet error, if defined.
///
/// It declares `type Module` type alias for `Pallet`, used by `construct_runtime`.
///
/// It implements [`PalletInfoAccess`](`traits::PalletInfoAccess') on `Pallet` to ease access
/// to pallet information given by [`frame_support::traits::PalletInfo`]. (The implementation
/// uses the associated type `frame_system::Config::PalletInfo`).
///
/// It implements [`StorageInfoTrait`](`traits::StorageInfoTrait`) on `Pallet` which give
/// information about all storages.
///
/// If the attribute `generate_store` is set then the macro creates the trait `Store` and
/// implements it on `Pallet`.
///
/// If the attribute `set_storage_max_encoded_len` is set then the macro calls
/// [`StorageInfoTrait`](`traits::StorageInfoTrait`) for each storage in the implementation of
/// [`StorageInfoTrait`](`traits::StorageInfoTrait`) for the pallet. Otherwise it implements
/// [`StorageInfoTrait`](`traits::StorageInfoTrait`) for the pallet using the
/// [`PartialStorageInfoTrait`](`traits::PartialStorageInfoTrait`) implementation of storages.
///
/// # Config trait: `#[pallet::config]` (mandatory)
///
/// The mandatory attribute `#[pallet::config]` defines the configurable options for the
/// pallet.
///
/// Item must be defined as:
///
/// ```ignore
/// #[pallet::config]
/// pub trait Config: frame_system::Config + $optionally_some_other_supertraits
/// $optional_where_clause
/// {
/// ...
/// }
/// ```
///
/// I.e. a regular trait definition named `Config`, with the supertrait
/// `frame_system::pallet::Config`, and optionally other supertraits and a where clause.
/// (Specifying other supertraits here is known as [tight
/// coupling](https://docs.substrate.io/reference/how-to-guides/pallet-design/use-tight-coupling/))
///
/// The associated type `RuntimeEvent` is reserved. If defined, it must have the bounds
/// `From<Event>` and `IsType<<Self as frame_system::Config>::RuntimeEvent>`.
///
/// [`pallet::event`](`frame_support::pallet_macros::event`) must be present if `RuntimeEvent`
/// exists as a config item in your `#[pallet::config]`.
///
/// Also see [`pallet::config`](`frame_support::pallet_macros::config`)
///
/// ## `pallet::constant`
///
/// The `#[pallet::constant]` attribute can be used to add an associated type trait bounded by
/// [`Get`](crate::traits::Get) from [`pallet::config`](#palletconfig) into metadata, e.g.:
///
/// ```ignore
/// #[pallet::config]
/// pub trait Config: frame_system::Config {
/// 	#[pallet::constant]
/// 	type Foo: Get<u32>;
/// }
/// ```
///
/// Also see [`pallet::constant`](`frame_support::pallet_macros::constant`)
///
/// ## `pallet::disable_frame_system_supertrait_check`
/// <a name="disable_supertrait_check"></a>
///
/// To bypass the `frame_system::Config` supertrait check, use the attribute
/// `pallet::disable_frame_system_supertrait_check`, e.g.:
///
/// ```ignore
/// #[pallet::config]
/// #[pallet::disable_frame_system_supertrait_check]
/// pub trait Config: pallet_timestamp::Config {}
/// ```
///
/// NOTE: Bypassing the `frame_system::Config` supertrait check is typically desirable when you
/// want to write an alternative to the `frame_system` pallet.
///
/// Also see
/// [`pallet::disable_frame_system_supertrait_check`](`frame_support::pallet_macros::disable_frame_system_supertrait_check`)
///
/// ## Macro expansion:
///
/// The macro expands pallet constant metadata with the information given by
/// `#[pallet::constant]`.
///
/// # `pallet::generate_store($vis trait Store)`
///
/// To generate a `Store` trait associating all storages, annotate your `Pallet` struct with
/// the attribute `#[pallet::generate_store($vis trait Store)]`, e.g.:
///
/// ```ignore
/// #[pallet::pallet]
/// #[pallet::generate_store(pub(super) trait Store)]
/// pub struct Pallet<T>(_);
/// ```
/// More precisely, the `Store` trait contains an associated type for each storage. It is
/// implemented for `Pallet` allowing access to the storage from pallet struct.
///
/// Thus when defining a storage named `Foo`, it can later be accessed from `Pallet` using
/// `<Pallet as Store>::Foo`.
///
/// NOTE: this attribute is only valid when applied _directly_ to your `Pallet` struct
/// definition.
///
/// Also see [`pallet::generate_store`](`frame_support::pallet_macros::generate_store`).
///
/// # `pallet::generate_storage_info`
///
/// To generate the full storage info (used for PoV calculation) use the attribute
/// `#[pallet::generate_storage_info]`, e.g.:
///
/// ```ignore
/// #[pallet::pallet]
/// #[pallet::generate_storage_info]
/// pub struct Pallet<T>(_);
/// ```
///
/// This requires all storage items to implement the trait [`traits::StorageInfoTrait`], thus
/// all keys and value types must be bound by [`pallet_prelude::MaxEncodedLen`]. Individual
/// storages can opt-out from this constraint by using `#[pallet::unbounded]` (see
/// `#[pallet::storage]` for more info).
///
/// Also see [`pallet::generate_storage_info`](`frame_support::pallet_macros::generate_storage_info`)
///
/// # `pallet::storage_version`
///
/// Because the [`pallet::pallet`](#pallet-struct-placeholder-palletpallet-mandatory) macro
/// implements [`traits::GetStorageVersion`], the current storage version needs to be
/// communicated to the macro. This can be done by using the `pallet::storage_version`
/// attribute:
///
/// ```ignore
/// const STORAGE_VERSION: StorageVersion = StorageVersion::new(5);
///
/// #[pallet::pallet]
/// #[pallet::storage_version(STORAGE_VERSION)]
/// pub struct Pallet<T>(_);
/// ```
///
/// If not present, the current storage version is set to the default value.
///
/// Also see [`pallet::storage_version`](`frame_support::pallet_macros::storage_version`)
///
/// # Hooks: `#[pallet::hooks]` (optional)
///
/// The `pallet::hooks` attribute allows you to specify a `Hooks` implementation for `Pallet`
/// that specifies pallet-specific logic.
///
/// The item the attribute attaches to must be defined as follows:
/// ```ignore
/// #[pallet::hooks]
/// impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> $optional_where_clause {
///     ...
/// }
/// ```
/// I.e. a regular trait implementation with generic bound: `T: Config`, for the trait
/// `Hooks<BlockNumberFor<T>>` (they are defined in preludes), for the type `Pallet<T>` and
/// with an optional where clause.
///
/// If no `#[pallet::hooks]` exists, then the following default implementation is
/// automatically generated:
/// ```ignore
/// #[pallet::hooks]
/// impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {}
/// ```
///
/// Also see [`pallet::hooks`](`frame_support::pallet_macros::hooks`)
///
/// # Call: `#[pallet::call]` (optional)
///
/// Implementation of pallet dispatchables.
///
/// Item must be defined as:
/// ```ignore
/// #[pallet::call]
/// impl<T: Config> Pallet<T> {
/// 	/// $some_doc
/// 	#[pallet::weight($ExpressionResultingInWeight)]
/// 	pub fn $fn_name(
/// 		origin: OriginFor<T>,
/// 		$some_arg: $some_type,
/// 		// or with compact attribute: #[pallet::compact] $some_arg: $some_type,
/// 		...
/// 	) -> DispatchResultWithPostInfo { // or `-> DispatchResult`
/// 		...
/// 	}
/// 	...
/// }
/// ```
/// I.e. a regular type implementation, with generic `T: Config`, on type `Pallet<T>`, with
/// an optional where clause.
///
/// ## `#[pallet::weight($expr)]`
///
/// Each dispatchable needs to define a weight with `#[pallet::weight($expr)]` attribute, the
/// first argument must be `origin: OriginFor<T>`.
///
/// Also see [`pallet::weight`](`frame_support::pallet_macros::weight`)
///
/// ### `#[pallet::compact] $some_arg: $some_type`
///
/// Compact encoding for arguments can be achieved via `#[pallet::compact]`. The function must
/// return a `DispatchResultWithPostInfo` or `DispatchResult`.
///
/// Also see [`pallet::compact`](`frame_support::pallet_macros::compact`)
///
/// ## `#[pallet::call_index($idx)]`
///
/// Each dispatchable may also be annotated with the `#[pallet::call_index($idx)]` attribute,
/// which explicitly defines the codec index for the dispatchable function in the `Call` enum.
///
/// All call indexes start from 0, until it encounters a dispatchable function with a defined
/// call index. The dispatchable function that lexically follows the function with a defined
/// call index will have that call index, but incremented by 1, e.g. if there are 3
/// dispatchable functions `fn foo`, `fn bar` and `fn qux` in that order, and only `fn bar`
/// has a call index of 10, then `fn qux` will have an index of 11, instead of 1.
///
/// **WARNING**: modifying dispatchables, changing their order, removing some, etc., must be
/// done with care. Indeed this will change the outer runtime call type (which is an enum with
/// one variant per pallet), this outer runtime call can be stored on-chain (e.g. in
/// `pallet-scheduler`). Thus migration might be needed. To mitigate against some of this, the
/// `#[pallet::call_index($idx)]` attribute can be used to fix the order of the dispatchable so
/// that the `Call` enum encoding does not change after modification. As a general rule of
/// thumb, it is therefore adventageous to always add new calls to the end so you can maintain
/// the existing order of calls.
///
/// Also see [`pallet::call_index`](`frame_support::pallet_macros::call_index`)
///
/// # Extra constants: `#[pallet::extra_constants]` (optional)
///
/// Allows you to define some extra constants to be added into constant metadata.
///
/// Item must be defined as:
///
/// ```ignore
/// #[pallet::extra_constants]
/// impl<T: Config> Pallet<T> where $optional_where_clause {
/// 	/// $some_doc
/// 	$vis fn $fn_name() -> $some_return_type {
/// 		...
/// 	}
/// 	...
/// }
/// ```
/// I.e. a regular rust `impl` block with some optional where clause and functions with 0 args,
/// 0 generics, and some return type.
///
/// ## Macro expansion
///
/// The macro add some extra constants to pallet constant metadata.
///
/// Also see: [`pallet::extra_constants`](`frame_support::pallet_macros::extra_constants`)
///
/// # Error: `#[pallet::error]` (optional)
///
/// The `#[pallet::error]` attribute allows you to define an error enum that will be returned
/// from the dispatchable when an error occurs. The information for this error type is then
/// stored in metadata.
///
/// Item must be defined as:
///
/// ```ignore
/// #[pallet::error]
/// pub enum Error<T> {
/// 	/// $some_optional_doc
/// 	$SomeFieldLessVariant,
/// 	/// $some_more_optional_doc
/// 	$SomeVariantWithOneField(FieldType),
/// 	...
/// }
/// ```
/// I.e. a regular enum named `Error`, with generic `T` and fieldless or multiple-field
/// variants.
///
/// Any field type in the enum variants must implement [`scale_info::TypeInfo`] in order to be
/// properly used in the metadata, and its encoded size should be as small as possible,
/// preferably 1 byte in size in order to reduce storage size. The error enum itself has an
/// absolute maximum encoded size specified by [`MAX_MODULE_ERROR_ENCODED_SIZE`].
///
/// (1 byte can still be 256 different errors. The more specific the error, the easier it is to
/// diagnose problems and give a better experience to the user. Don't skimp on having lots of
/// individual error conditions.)
///
/// Field types in enum variants must also implement [`PalletError`](traits::PalletError),
/// otherwise the pallet will fail to compile. Rust primitive types have already implemented
/// the [`PalletError`](traits::PalletError) trait along with some commonly used stdlib types
/// such as [`Option`] and [`PhantomData`](`frame_support::dispatch::marker::PhantomData`), and
/// hence in most use cases, a manual implementation is not necessary and is discouraged.
///
/// The generic `T` must not bound anything and a `where` clause is not allowed. That said,
/// bounds and/or a where clause should not needed for any use-case.
///
/// Also see: [`pallet::error`](`frame_support::pallet_macros::error`)
///
/// # Event: `#[pallet::event]` (optional)
///
/// Allows you to define pallet events. Pallet events are stored under the `system` / `events`
/// key when the block is applied (and then replaced when the next block writes it's events).
///
/// The Event enum must be defined as follows:
///
/// ```ignore
/// #[pallet::event]
/// #[pallet::generate_deposit($visibility fn deposit_event)] // Optional
/// pub enum Event<$some_generic> $optional_where_clause {
/// 	/// Some doc
/// 	$SomeName($SomeType, $YetanotherType, ...),
/// 	...
/// }
/// ```
///
/// I.e. an enum (with named or unnamed fields variant), named `Event`, with generic: none or
/// `T` or `T: Config`, and optional w here clause.
///
/// Each field must implement [`Clone`], [`Eq`], [`PartialEq`], [`Encode`], [`Decode`], and
/// [`Debug`] (on std only). For ease of use, bound by the trait
/// [`Member`](`frame_support::pallet_prelude::Member`), available in
/// frame_support::pallet_prelude.
///
/// Also see [`pallet::event`](`frame_support::pallet_macros::event`)
///
/// ## `#[pallet::generate_deposit($visibility fn deposit_event)]`
///
/// The attribute `#[pallet::generate_deposit($visibility fn deposit_event)]` generates a
/// helper function on `Pallet` that handles deposit events.
///
/// NOTE: For instantiable pallets, the event must be generic over `T` and `I`.
///
/// Also see [`pallet::generate_deposit`](`frame_support::pallet_macros::generate_deposit`)
///
/// # Storage: `#[pallet::storage]` (optional)
///
/// The `#[pallet::storage]` attribute lets you define some abstract storage inside of runtime
/// storage and also set its metadata. This attribute can be used multiple times.
///
/// Item should be defined as:
///
/// ```ignore
/// #[pallet::storage]
/// #[pallet::getter(fn $getter_name)] // optional
/// $vis type $StorageName<$some_generic> $optional_where_clause
/// 	= $StorageType<$generic_name = $some_generics, $other_name = $some_other, ...>;
/// ```
///
/// or with unnamed generic:
///
/// ```ignore
/// #[pallet::storage]
/// #[pallet::getter(fn $getter_name)] // optional
/// $vis type $StorageName<$some_generic> $optional_where_clause
/// 	= $StorageType<_, $some_generics, ...>;
/// ```
///
/// I.e. it must be a type alias, with generics: `T` or `T: Config`. The aliased type must be
/// one of [`StorageValue`](`pallet_prelude::StorageValue`),
/// [`StorageMap`](`pallet_prelude::StorageMap`) or
/// [`StorageDoubleMap`](`pallet_prelude::StorageDoubleMap`). The generic arguments of the
/// storage type can be given in two manners: named and unnamed. For named generic arguments,
/// the name for each argument should match the name defined for it on the storage struct:
/// * [`StorageValue`](`pallet_prelude::StorageValue`) expects `Value` and optionally
///   `QueryKind` and `OnEmpty`,
/// * [`StorageMap`](`pallet_prelude::StorageMap`) expects `Hasher`, `Key`, `Value` and
///   optionally `QueryKind` and `OnEmpty`,
/// * [`CountedStorageMap`](`pallet_prelude::CountedStorageMap`) expects `Hasher`, `Key`,
///   `Value` and optionally `QueryKind` and `OnEmpty`,
/// * [`StorageDoubleMap`](`pallet_prelude::StorageDoubleMap`) expects `Hasher1`, `Key1`,
///   `Hasher2`, `Key2`, `Value` and optionally `QueryKind` and `OnEmpty`.
///
/// For unnamed generic arguments: Their first generic must be `_` as it is replaced by the
/// macro and other generic must declared as a normal generic type declaration.
///
/// The `Prefix` generic written by the macro is generated using
/// `PalletInfo::name::<Pallet<..>>()` and the name of the storage type. E.g. if runtime names
/// the pallet "MyExample" then the storage `type Foo<T> = ...` should use the prefix:
/// `Twox128(b"MyExample") ++ Twox128(b"Foo")`.
///
/// For the [`CountedStorageMap`](`pallet_prelude::CountedStorageMap`) variant, the `Prefix`
/// also implements
/// [`CountedStorageMapInstance`](`frame_support::storage::types::CountedStorageMapInstance`).
/// It also associates a [`CounterPrefix`](`pallet_prelude::CounterPrefix'), which is
/// implemented the same as above, but the storage prefix is prepend with `"CounterFor"`. E.g.
/// if runtime names the pallet "MyExample" then the storage `type Foo<T> =
/// CountedStorageaMap<...>` will store its counter at the prefix: `Twox128(b"MyExample") ++
/// Twox128(b"CounterForFoo")`.
///
/// E.g:
///
/// ```ignore
/// #[pallet::storage]
/// pub(super) type MyStorage<T> = StorageMap<Hasher = Blake2_128Concat, Key = u32, Value = u32>;
/// ```
///
/// In this case the final prefix used by the map is `Twox128(b"MyExample") ++
/// Twox128(b"OtherName")`.
///
/// Also see [`pallet::storage`](`frame_support::pallet_macros::storage`)
///
/// ## `#[pallet::getter(fn $my_getter_fn_name)]` (optional)
///
/// The optional attribute `#[pallet::getter(fn $my_getter_fn_name)]` allows you to define a
/// getter function on `Pallet`.
///
/// Also see [`pallet::getter`](`frame_support::pallet_macros::getter`)
///
/// ## `#[pallet::storage_prefix = "SomeName"]` (optional)
///
/// The optional attribute `#[pallet::storage_prefix = "SomeName"]` allows you to define the
/// storage prefix to use, see how `Prefix` generic is implemented above. This is helpful if
/// you wish to rename the storage field but don't want to perform a migration.
///
/// E.g:
///
/// ```ignore
/// #[pallet::storage]
/// #[pallet::storage_prefix = "foo"]
/// #[pallet::getter(fn my_storage)]
/// pub(super) type MyStorage<T> = StorageMap<Hasher = Blake2_128Concat, Key = u32, Value = u32>;
/// ```
///
/// or
///
/// ```ignore
/// #[pallet::storage]
/// #[pallet::getter(fn my_storage)]
/// pub(super) type MyStorage<T> = StorageMap<_, Blake2_128Concat, u32, u32>;
/// ```
///
/// Also see [`pallet::storage_prefix`](`frame_support::pallet_macros::storage_prefix`)
///
/// ## `#[pallet::unbounded]` (optional)
///
/// The optional attribute `#[pallet::unbounded]` declares the storage as unbounded. When
/// implementating the storage info (when `#[pallet::generate_storage_info]` is specified on
/// the pallet struct placeholder), the size of the storage will be declared as unbounded. This
/// can be useful for storage which can never go into PoV (Proof of Validity).
///
/// Also see [`pallet::unbounded`](`frame_support::pallet_macros::unbounded`)
///
/// ## `#[pallet::whitelist_storage]` (optional)
///
/// The optional attribute `#[pallet::whitelist_storage]` will declare the storage as
/// whitelisted from benchmarking.
///
/// See
/// [`pallet::whitelist_storage`](frame_support::pallet_macros::whitelist_storage)
/// for more info.
///
///	## `#[cfg(..)]` (for storage)
/// The optional attributes `#[cfg(..)]` allow conditional compilation for the storage.
///
/// E.g:
///
/// ```ignore
/// #[cfg(feature = "my-feature")]
/// #[pallet::storage]
/// pub(super) type MyStorage<T> = StorageValue<Value = u32>;
/// ```
///
/// All the `cfg` attributes are automatically copied to the items generated for the storage,
/// i.e. the getter, storage prefix, and the metadata element etc.
///
/// Any type placed as the `QueryKind` parameter must implement
/// [`frame_support::storage::types::QueryKindTrait`]. There are 3 implementations of this
/// trait by default:
///
/// 1. [`OptionQuery`](`frame_support::storage::types::OptionQuery`), the default `QueryKind`
///    used when this type parameter is omitted. Specifying this as the `QueryKind` would cause
///    storage map APIs that return a `QueryKind` to instead return an [`Option`], returning
///    `Some` when a value does exist under a specified storage key, and `None` otherwise.
/// 2. [`ValueQuery`](`frame_support::storage::types::ValueQuery`) causes storage map APIs that
///    return a `QueryKind` to instead return the value type. In cases where a value does not
///    exist under a specified storage key, the `OnEmpty` type parameter on `QueryKindTrait` is
///    used to return an appropriate value.
/// 3. [`ResultQuery`](`frame_support::storage::types::ResultQuery`) causes storage map APIs
///    that return a `QueryKind` to instead return a `Result<T, E>`, with `T` being the value
///    type and `E` being the pallet error type specified by the `#[pallet::error]` attribute.
///    In cases where a value does not exist under a specified storage key, an `Err` with the
///    specified pallet error variant is returned.
///
/// NOTE: If the `QueryKind` generic parameter is still generic at this stage or is using some
/// type alias then the generation of the getter might fail. In this case the getter can be
/// implemented manually.
///
/// NOTE: The generic `Hasher` must implement the [`StorageHasher`] trait (or the type is not
/// usable at all). We use [`StorageHasher::METADATA`] for the metadata of the hasher of the
/// storage item. Thus generic hasher is supported.
///
/// ## Macro expansion
///
/// For each storage item the macro generates a struct named
/// `_GeneratedPrefixForStorage$NameOfStorage`, and implements
/// [`StorageInstance`](traits::StorageInstance) on it using the pallet and storage name. It
/// then uses it as the first generic of the aliased type. For
/// [`CountedStorageMap`](`pallet_prelude::CountedStorageMap`),
/// [`CountedStorageMapInstance`](`frame_support::storage::types::CountedStorageMapInstance`)
/// is implemented, and another similar struct is generated.
///
/// For a named generic, the macro will reorder the generics, and remove the names.
///
/// The macro implements the function `storage_metadata` on the `Pallet` implementing the
/// metadata for all storage items based on their kind:
/// * for a storage value, the type of the value is copied into the metadata
/// * for a storage map, the type of the values and the key's type is copied into the metadata
/// * for a storage double map, the type of the values, and the types of `key1` and `key2` are
///   copied into the metadata.
///
/// # Type value: `#[pallet::type_value]` (optional)
///
/// The `#[pallet::type_value]` attribute lets you define a struct implementing the
/// [`Get`](crate::traits::Get) trait to ease use of storage types. This attribute is meant to
/// be used alongside [`#[pallet::storage]`](#storage-palletstorage-optional) to define a
/// storage's default value. This attribute can be used multiple times.
///
/// Item must be defined as:
///
/// ```ignore
/// #[pallet::type_value]
/// fn $MyDefaultName<$some_generic>() -> $default_type $optional_where_clause { $expr }
/// ```
///
/// I.e.: a function definition with generics none or `T: Config` and a returned type.
///
/// E.g.:
///
/// ```ignore
/// #[pallet::type_value]
/// fn MyDefault<T: Config>() -> T::Balance { 3.into() }
/// ```
///
/// Also see [`pallet::type_value`](`frame_support::pallet_macros::type_value`)
///
/// # Genesis config: `#[pallet::genesis_config]` (optional)
///
/// The `#[pallet::genesis_config]` attribute allows you to define the genesis configuration
/// for the pallet.
///
/// Item is defined as either an enum or a struct. It needs to be public and implement the
/// trait [`GenesisBuild`](`traits::GenesisBuild`) with
/// [`#[pallet::genesis_build]`](#genesis-build-palletgenesis_build-optional). The type
/// generics are constrained to be either none, or `T` or `T: Config`.
///
/// E.g:
///
/// ```ignore
/// #[pallet::genesis_config]
/// pub struct GenesisConfig<T: Config> {
/// 	_myfield: BalanceOf<T>,
/// }
/// ```
///
/// Also see [`pallet::genesis_config`](`frame_support::pallet_macros::genesis_config`)
///
/// # Genesis build: `#[pallet::genesis_build]` (optional)
///
/// The `#[pallet::genesis_build]` attribute allows you to define how `genesis_configuration`
/// is built. This takes as input the `GenesisConfig` type (as `self`) and constructs the
/// pallet's initial state.
///
/// The impl must be defined as:
///
/// ```ignore
/// #[pallet::genesis_build]
/// impl<T: Config> GenesisBuild<T> for GenesisConfig<$maybe_generics> {
/// 	fn build(&self) { $expr }
/// }
/// ```
///
/// I.e. a trait implementation with generic `T: Config`, of trait `GenesisBuild<T>` on
/// type `GenesisConfig` with generics none or `T`.
///
/// E.g.:
///
/// ```ignore
/// #[pallet::genesis_build]
/// impl<T: Config> GenesisBuild<T> for GenesisConfig {
/// 	fn build(&self) {}
/// }
/// ```
///
/// Also see [`pallet::genesis_build`](`frame_support::pallet_macros::genesis_build`)
///
/// # Inherent: `#[pallet::inherent]` (optional)
///
/// The `#[pallet::inherent]` attribute allows the pallet to provide some
/// [inherent](https://docs.substrate.io/fundamentals/transaction-types/#inherent-transactions).
/// An inherent is some piece of data that is inserted by a block authoring node at block
/// creation time and can either be accepted or rejected by validators based on whether the
/// data falls within an acceptable range.
///
/// The most common inherent is the `timestamp` that is inserted into every block. Since there
/// is no way to validate timestamps, validators simply check that the timestamp reported by
/// the block authoring node falls within an acceptable range.
///
/// Item must be defined as:
///
/// ```ignore
/// #[pallet::inherent]
/// impl<T: Config> ProvideInherent for Pallet<T> {
/// 	// ... regular trait implementation
/// }
/// ```
///
/// I.e. a trait implementation with bound `T: Config`, of trait
/// [`ProvideInherent`](`pallet_prelude::ProvideInherent`) for type `Pallet<T>`, and some
/// optional where clause.
///
/// Also see [`pallet::inherent`](`frame_support::pallet_macros::inherent`)
///
/// # Validate unsigned: `#[pallet::validate_unsigned]` (optional)
///
/// The `#[pallet::validate_unsigned]` attribute allows the pallet to validate some unsigned
/// transaction:
///
/// Item must be defined as:
///
/// ```ignore
/// #[pallet::validate_unsigned]
/// impl<T: Config> ValidateUnsigned for Pallet<T> {
/// 	// ... regular trait implementation
/// }
/// ```
///
/// I.e. a trait implementation with bound `T: Config`, of trait
/// [`ValidateUnsigned`](`pallet_prelude::ValidateUnsigned`) for type `Pallet<T>`, and some
/// optional where clause.
///
/// NOTE: There is also the [`sp_runtime::traits::SignedExtension`] trait that can be used to
/// add some specific logic for transaction validation.
///
/// Also see [`pallet::validate_unsigned`](`frame_support::pallet_macros::validate_unsigned`)
///
/// # Origin: `#[pallet::origin]` (optional)
///
/// The `#[pallet::origin]` attribute allows you to define some origin for the pallet.
///
/// Item must be either a type alias, an enum, or a struct. It needs to be public.
///
/// E.g.:
///
/// ```ignore
/// #[pallet::origin]
/// pub struct Origin<T>(PhantomData<(T)>);
/// ```
///
/// **WARNING**: modifying origin changes the outer runtime origin. This outer runtime origin
/// can be stored on-chain (e.g. in `pallet-scheduler`), thus any change must be done with care
/// as it might require some migration.
///
/// NOTE: for instantiable pallets, the origin must be generic over `T` and `I`.
///
/// Also see [`pallet::origin`](`frame_support::pallet_macros::origin`)
///
/// # General notes on instantiable pallets
///
/// An instantiable pallet is one where Config is generic, i.e. `Config<I>`. This allows
/// runtime to implement multiple instances of the pallet, by using different types for the
/// generic. This is the sole purpose of the generic `I`, but because
/// [`PalletInfo`](`traits::PalletInfo`) requires the `Pallet` placeholder to be static, it is
/// important to bound by `'static` whenever [`PalletInfo`](`traits::PalletInfo`) can be used.
/// Additionally, in order to make an instantiable pallet usable as a regular pallet without an
/// instance, it is important to bound by `= ()` on every type.
///
/// Thus impl bound looks like `impl<T: Config<I>, I: 'static>`, and types look like
/// `SomeType<T, I=()>` or `SomeType<T: Config<I>, I: 'static = ()>`.
///
/// # Example of a non-instantiable pallet
///
/// ```
/// pub use pallet::*; // reexport in crate namespace for `construct_runtime!`
///
/// #[frame_support::pallet]
/// // NOTE: The name of the pallet is provided by `construct_runtime` and is used as
/// // the unique identifier for the pallet's storage. It is not defined in the pallet itself.
/// pub mod pallet {
/// 	use frame_support::pallet_prelude::*; // Import various types used in the pallet definition
/// 	use frame_system::pallet_prelude::*; // Import some system helper types.
///
/// 	type BalanceOf<T> = <T as Config>::Balance;
///
/// 	// Define the generic parameter of the pallet
/// 	// The macro parses `#[pallet::constant]` attributes and uses them to generate metadata
/// 	// for the pallet's constants.
/// 	#[pallet::config]
/// 	pub trait Config: frame_system::Config {
/// 		#[pallet::constant] // put the constant in metadata
/// 		type MyGetParam: Get<u32>;
/// 		type Balance: Parameter + MaxEncodedLen + From<u8>;
/// 		type RuntimeEvent: From<Event<Self>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
/// 	}
///
/// 	// Define some additional constant to put into the constant metadata.
/// 	#[pallet::extra_constants]
/// 	impl<T: Config> Pallet<T> {
/// 		/// Some description
/// 		fn exra_constant_name() -> u128 { 4u128 }
/// 	}
///
/// 	// Define the pallet struct placeholder, various pallet function are implemented on it.
/// 	#[pallet::pallet]
/// 	#[pallet::generate_store(pub(super) trait Store)]
/// 	pub struct Pallet<T>(_);
///
/// 	// Implement the pallet hooks.
/// 	#[pallet::hooks]
/// 	impl<T: Config> Hooks<BlockNumberFor<T>> for Pallet<T> {
/// 		fn on_initialize(_n: BlockNumberFor<T>) -> Weight {
/// 			unimplemented!();
/// 		}
///
/// 		// can implement also: on_finalize, on_runtime_upgrade, offchain_worker, ...
/// 		// see `Hooks` trait
/// 	}
///
/// 	// Declare Call struct and implement dispatchables.
/// 	//
/// 	// WARNING: Each parameter used in functions must implement: Clone, Debug, Eq, PartialEq,
/// 	// Codec.
/// 	//
/// 	// The macro parses `#[pallet::compact]` attributes on function arguments and implements
/// 	// the `Call` encoding/decoding accordingly.
/// 	#[pallet::call]
/// 	impl<T: Config> Pallet<T> {
/// 		/// Doc comment put in metadata
/// 		#[pallet::weight(0)] // Defines weight for call (function parameters are in scope)
/// 		pub fn toto(
/// 			origin: OriginFor<T>,
/// 			#[pallet::compact] _foo: u32,
/// 		) -> DispatchResultWithPostInfo {
/// 			let _ = origin;
/// 			unimplemented!();
/// 		}
/// 	}
///
/// 	// Declare the pallet `Error` enum (this is optional).
/// 	// The macro generates error metadata using the doc comment on each variant.
/// 	#[pallet::error]
/// 	pub enum Error<T> {
/// 		/// doc comment put into metadata
/// 		InsufficientProposersBalance,
/// 	}
///
/// 	// Declare pallet Event enum (this is optional).
/// 	//
/// 	// WARNING: Each type used in variants must implement: Clone, Debug, Eq, PartialEq, Codec.
/// 	//
/// 	// The macro generates event metadata, and derive Clone, Debug, Eq, PartialEq and Codec
/// 	#[pallet::event]
/// 	// Generate a funciton on Pallet to deposit an event.
/// 	#[pallet::generate_deposit(pub(super) fn deposit_event)]
/// 	pub enum Event<T: Config> {
/// 		/// doc comment put in metadata
/// 		// `<T as frame_system::Config>::AccountId` is not defined in metadata list, the last
/// 		// Thus the metadata is `<T as frame_system::Config>::AccountId`.
/// 		Proposed(<T as frame_system::Config>::AccountId),
/// 		/// doc
/// 		// here metadata will be `Balance` as define in metadata list
/// 		Spending(BalanceOf<T>),
/// 		// here metadata will be `Other` as define in metadata list
/// 		Something(u32),
/// 	}
///
/// 	// Define a struct which implements `frame_support::traits::Get<T::Balance>` (optional).
/// 	#[pallet::type_value]
/// 	pub(super) fn MyDefault<T: Config>() -> T::Balance { 3.into() }
///
/// 	// Declare a storage item. Any amount of storage items can be declared (optional).
/// 	//
/// 	// Is expected either `StorageValue`, `StorageMap` or `StorageDoubleMap`.
/// 	// The macro generates the prefix type and replaces the first generic `_`.
/// 	//
/// 	// The macro expands the metadata for the storage item with the type used:
/// 	// * for a storage value the type of the value is copied into the metadata
/// 	// * for a storage map the type of the values and the type of the key is copied into the metadata
/// 	// * for a storage double map the types of the values and keys are copied into the
/// 	//   metadata.
/// 	//
/// 	// NOTE: The generic `Hasher` must implement the `StorageHasher` trait (or the type is not
/// 	// usable at all). We use [`StorageHasher::METADATA`] for the metadata of the hasher of the
/// 	// storage item. Thus generic hasher is supported.
/// 	#[pallet::storage]
/// 	pub(super) type MyStorageValue<T: Config> =
/// 		StorageValue<Value = T::Balance, QueryKind = ValueQuery, OnEmpty = MyDefault<T>>;
///
/// 	// Another storage declaration
/// 	#[pallet::storage]
/// 	#[pallet::getter(fn my_storage)]
/// 	#[pallet::storage_prefix = "SomeOtherName"]
/// 	pub(super) type MyStorage<T> =
/// 		StorageMap<Hasher = Blake2_128Concat, Key = u32, Value = u32>;
///
/// 	// Declare the genesis config (optional).
/// 	//
/// 	// The macro accepts either a struct or an enum; it checks that generics are consistent.
/// 	//
/// 	// Type must implement the `Default` trait.
/// 	#[pallet::genesis_config]
/// 	#[derive(Default)]
/// 	pub struct GenesisConfig {
/// 		_myfield: u32,
/// 	}
///
/// 	// Declare genesis builder. (This is need only if GenesisConfig is declared)
/// 	#[pallet::genesis_build]
/// 	impl<T: Config> GenesisBuild<T> for GenesisConfig {
/// 		fn build(&self) {}
/// 	}
///
/// 	// Declare a pallet origin (this is optional).
/// 	//
/// 	// The macro accept type alias or struct or enum, it checks generics are consistent.
/// 	#[pallet::origin]
/// 	pub struct Origin<T>(PhantomData<T>);
///
/// 	// Declare validate_unsigned implementation (this is optional).
/// 	#[pallet::validate_unsigned]
/// 	impl<T: Config> ValidateUnsigned for Pallet<T> {
/// 		type Call = Call<T>;
/// 		fn validate_unsigned(
/// 			source: TransactionSource,
/// 			call: &Self::Call
/// 		) -> TransactionValidity {
/// 			Err(TransactionValidityError::Invalid(InvalidTransaction::Call))
/// 		}
/// 	}
///
/// 	// Declare inherent provider for pallet (this is optional).
/// 	#[pallet::inherent]
/// 	impl<T: Config> ProvideInherent for Pallet<T> {
/// 		type Call = Call<T>;
/// 		type Error = InherentError;
///
/// 		const INHERENT_IDENTIFIER: InherentIdentifier = INHERENT_IDENTIFIER;
///
/// 		fn create_inherent(_data: &InherentData) -> Option<Self::Call> {
/// 			unimplemented!();
/// 		}
///
/// 		fn is_inherent(_call: &Self::Call) -> bool {
/// 			unimplemented!();
/// 		}
/// 	}
///
/// 	// Regular rust code needed for implementing ProvideInherent trait
///
/// 	#[derive(codec::Encode, sp_runtime::RuntimeDebug)]
/// 	#[cfg_attr(feature = "std", derive(codec::Decode))]
/// 	pub enum InherentError {
/// 	}
///
/// 	impl sp_inherents::IsFatalError for InherentError {
/// 		fn is_fatal_error(&self) -> bool {
/// 			unimplemented!();
/// 		}
/// 	}
///
/// 	pub const INHERENT_IDENTIFIER: sp_inherents::InherentIdentifier = *b"testpall";
/// }
/// ```
///
/// # Example of an instantiable pallet
///
/// ```
/// pub use pallet::*;
///
/// #[frame_support::pallet]
/// pub mod pallet {
/// 	use frame_support::pallet_prelude::*;
/// 	use frame_system::pallet_prelude::*;
///
/// 	type BalanceOf<T, I = ()> = <T as Config<I>>::Balance;
///
/// 	#[pallet::config]
/// 	pub trait Config<I: 'static = ()>: frame_system::Config {
/// 		#[pallet::constant]
/// 		type MyGetParam: Get<u32>;
/// 		type Balance: Parameter + MaxEncodedLen + From<u8>;
/// 		type RuntimeEvent: From<Event<Self, I>> + IsType<<Self as frame_system::Config>::RuntimeEvent>;
/// 	}
///
/// 	#[pallet::extra_constants]
/// 	impl<T: Config<I>, I: 'static> Pallet<T, I> {
/// 		/// Some description
/// 		fn exra_constant_name() -> u128 { 4u128 }
/// 	}
///
/// 	#[pallet::pallet]
/// 	#[pallet::generate_store(pub(super) trait Store)]
/// 	pub struct Pallet<T, I = ()>(PhantomData<(T, I)>);
///
/// 	#[pallet::hooks]
/// 	impl<T: Config<I>, I: 'static> Hooks<BlockNumberFor<T>> for Pallet<T, I> {
/// 	}
///
/// 	#[pallet::call]
/// 	impl<T: Config<I>, I: 'static> Pallet<T, I> {
/// 		/// Doc comment put in metadata
/// 		#[pallet::weight(0)]
/// 		pub fn toto(origin: OriginFor<T>, #[pallet::compact] _foo: u32) -> DispatchResultWithPostInfo {
/// 			let _ = origin;
/// 			unimplemented!();
/// 		}
/// 	}
///
/// 	#[pallet::error]
/// 	pub enum Error<T, I = ()> {
/// 		/// doc comment put into metadata
/// 		InsufficientProposersBalance,
/// 	}
///
/// 	#[pallet::event]
/// 	#[pallet::generate_deposit(pub(super) fn deposit_event)]
/// 	pub enum Event<T: Config<I>, I: 'static = ()> {
/// 		/// doc comment put in metadata
/// 		Proposed(<T as frame_system::Config>::AccountId),
/// 		/// doc
/// 		Spending(BalanceOf<T, I>),
/// 		Something(u32),
/// 	}
///
/// 	#[pallet::type_value]
/// 	pub(super) fn MyDefault<T: Config<I>, I: 'static>() -> T::Balance { 3.into() }
///
/// 	#[pallet::storage]
/// 	pub(super) type MyStorageValue<T: Config<I>, I: 'static = ()> =
/// 		StorageValue<Value = T::Balance, QueryKind = ValueQuery, OnEmpty = MyDefault<T, I>>;
///
/// 	#[pallet::storage]
/// 	#[pallet::getter(fn my_storage)]
/// 	#[pallet::storage_prefix = "SomeOtherName"]
/// 	pub(super) type MyStorage<T, I = ()> =
/// 		StorageMap<Hasher = Blake2_128Concat, Key = u32, Value = u32>;
///
/// 	#[pallet::genesis_config]
/// 	#[derive(Default)]
/// 	pub struct GenesisConfig {
/// 		_myfield: u32,
/// 	}
///
/// 	#[pallet::genesis_build]
/// 	impl<T: Config<I>, I: 'static> GenesisBuild<T, I> for GenesisConfig {
/// 		fn build(&self) {}
/// 	}
///
/// 	#[pallet::origin]
/// 	pub struct Origin<T, I = ()>(PhantomData<(T, I)>);
///
/// 	#[pallet::validate_unsigned]
/// 	impl<T: Config<I>, I: 'static> ValidateUnsigned for Pallet<T, I> {
/// 		type Call = Call<T, I>;
/// 		fn validate_unsigned(
/// 			source: TransactionSource,
/// 			call: &Self::Call
/// 		) -> TransactionValidity {
/// 			Err(TransactionValidityError::Invalid(InvalidTransaction::Call))
/// 		}
/// 	}
///
/// 	#[pallet::inherent]
/// 	impl<T: Config<I>, I: 'static> ProvideInherent for Pallet<T, I> {
/// 		type Call = Call<T, I>;
/// 		type Error = InherentError;
///
/// 		const INHERENT_IDENTIFIER: InherentIdentifier = INHERENT_IDENTIFIER;
///
/// 		fn create_inherent(_data: &InherentData) -> Option<Self::Call> {
/// 			unimplemented!();
/// 		}
///
/// 		fn is_inherent(_call: &Self::Call) -> bool {
/// 			unimplemented!();
/// 		}
/// 	}
///
/// 	// Regular rust code needed for implementing ProvideInherent trait
///
/// 	#[derive(codec::Encode, sp_runtime::RuntimeDebug)]
/// 	#[cfg_attr(feature = "std", derive(codec::Decode))]
/// 	pub enum InherentError {
/// 	}
///
/// 	impl sp_inherents::IsFatalError for InherentError {
/// 		fn is_fatal_error(&self) -> bool {
/// 			unimplemented!();
/// 		}
/// 	}
///
/// 	pub const INHERENT_IDENTIFIER: sp_inherents::InherentIdentifier = *b"testpall";
/// }
/// ```
///
/// # Upgrade guidelines
///
/// 1. Export the metadata of the pallet for later checks
///     - run your node with the pallet active
///     - query the metadata using the `state_getMetadata` RPC and curl, or use `subsee -p
///       <PALLET_NAME> > meta.json`
/// 2. Generate the template upgrade for the pallet provided by `decl_storage` with the
///     environment variable `PRINT_PALLET_UPGRADE`: `PRINT_PALLET_UPGRADE=1 cargo check -p
///     my_pallet`. This template can be used as it contains all information for storages,
///     genesis config and genesis build.
/// 3. Reorganize the pallet to have the trait `Config`, `decl_*` macros,
///     [`ValidateUnsigned`](`pallet_prelude::ValidateUnsigned`),
///     [`ProvideInherent`](`pallet_prelude::ProvideInherent`), and Origin` all together in one
///     file. Suggested order:
///     * `Config`,
///     * `decl_module`,
///     * `decl_event`,
///     * `decl_error`,
///     * `decl_storage`,
///     * `origin`,
///     * `validate_unsigned`,
///     * `provide_inherent`, so far it should compile and all be correct.
/// 4. start writing the new pallet module
/// 	```ignore
/// 	pub use pallet::*;
///
/// 	#[frame_support::pallet]
/// 	pub mod pallet {
/// 		use frame_support::pallet_prelude::*;
/// 		use frame_system::pallet_prelude::*;
/// 		use super::*;
///
/// 		#[pallet::pallet]
/// 		#[pallet::generate_store($visibility_of_trait_store trait Store)]
/// 		// NOTE: if the visibility of trait store is private but you want to make it available
/// 		// in super, then use `pub(super)` or `pub(crate)` to make it available in crate.
/// 		pub struct Pallet<T>(_);
/// 		// pub struct Pallet<T, I = ()>(PhantomData<T>); // for instantiable pallet
/// 	}
/// 	```
/// 5. **migrate Config**: move trait into the module with
///     * all const in `decl_module` to [`#[pallet::constant]`](#palletconstant)
///     * add the bound `IsType<<Self as frame_system::Config>::RuntimeEvent>` to `type
///       RuntimeEvent`
/// 7. **migrate decl_module**: write:
/// 	```ignore
/// 	#[pallet::hooks]
/// 	impl<T: Config> Hooks for Pallet<T> {
/// 	}
/// 	```
///     and write inside `on_initialize`, `on_finalize`, `on_runtime_upgrade`,
///     `offchain_worker`, and `integrity_test`.
///
/// 	then write:
/// 	```ignore
/// 	#[pallet::call]
/// 	impl<T: Config> Pallet<T> {
/// 	}
/// 	```
///     and write inside all the calls in `decl_module` with a few changes in the signature:
///     - origin must now be written completely, e.g. `origin: OriginFor<T>`
///     - result type must be `DispatchResultWithPostInfo`, you need to write it and also you
///    might need to put `Ok(().into())` at the end or the function.
///     - `#[compact]` must now be written
///       [`#[pallet::compact]`](#palletcompact-some_arg-some_type)
///     - `#[weight = ..]` must now be written [`#[pallet::weight(..)]`](#palletweightexpr)
///
/// 7. **migrate event**: rewrite as a simple enum with the attribute
///    [`#[pallet::event]`](#event-palletevent-optional), use [`#[pallet::generate_deposit($vis
///    fn deposit_event)]`](#event-palletevent-optional) to generate `deposit_event`,
/// 8. **migrate error**: rewrite it with attribute
///    [`#[pallet::error]`](#error-palleterror-optional).
/// 9. **migrate storage**: `decl_storage` provide an upgrade template (see 3.). All storages,
///     genesis config, genesis build and default implementation of genesis config can be
///     taken from it directly.
///
///     Otherwise here is the manual process:
///
///     first migrate the genesis logic. write:
/// 	```ignore
/// 	#[pallet::genesis_config]
/// 	struct GenesisConfig {
/// 		// fields of add_extra_genesis
/// 	}
/// 	impl Default for GenesisConfig {
/// 		// type default or default provided for fields
/// 	}
/// 	#[pallet::genesis_build]
/// 	impl<T: Config> GenesisBuild<T> for GenesisConfig {
/// 	// for instantiable pallet:
/// 	// `impl<T: Config, I: 'static> GenesisBuild<T, I> for GenesisConfig {
/// 		fn build() {
/// 			// The add_extra_genesis build logic
/// 		}
/// 	}
/// 	```
///     for each storage, if it contains `config(..)` then add fields, and make it default to
///     the value in `= ..;` or the type default if none, if it contains no build then also add
///     the logic to build the value. for each storage if it contains `build(..)` then add the
///     logic to `genesis_build`.
///
///     NOTE: within `decl_storage`: the individual config is executed first, followed by the
///     build and finally the `add_extra_genesis` build.
///
///     Once this is done you can migrate storages individually, a few notes:
///     - for private storage use `pub(crate) type ` or `pub(super) type` or nothing,
///     - for storages with `get(fn ..)` use [`#[pallet::getter(fn
///       ...)]`](#palletgetterfn-my_getter_fn_name-optional)
///     - for storages with value being `Option<$something>` make generic `Value` being
///       `$something` and generic `QueryKind` being `OptionQuery` (note: this is default).
///       Otherwise make `Value` the complete value type and `QueryKind` being `ValueQuery`.
///     - for storages with default value: `= $expr;` provide some specific `OnEmpty` generic.
///       To do so use of `#[pallet::type_value]` to generate the wanted struct to put.
///       example: `MyStorage: u32 = 3u32` would be written:
///
/// 	  	```ignore
/// 		#[pallet::type_value] fn MyStorageOnEmpty() -> u32 { 3u32 }
/// 		#[pallet::storage]
/// 		pub(super) type MyStorage<T> = StorageValue<_, u32, ValueQuery, MyStorageOnEmpty>;
/// 		```
///
///       NOTE: `decl_storage` also generates the functions `assimilate_storage` and
///       `build_storage` directly on `GenesisConfig`, and these are sometimes used in tests.
///       In order not to break they can be implemented manually, one can implement those
///       functions by calling the `GenesisBuild` implementation.
/// 10. **migrate origin**: move the origin to the pallet module to be under a
///     [`#[pallet::origin]`](#origin-palletorigin-optional) attribute
/// 11. **migrate validate_unsigned**: move the
///     [`ValidateUnsigned`](`pallet_prelude::ValidateUnsigned`) implementation to the pallet
///     module under a
///     [`#[pallet::validate_unsigned]`](#validate-unsigned-palletvalidate_unsigned-optional)
///     attribute
/// 12. **migrate provide_inherent**: move the
///     [`ProvideInherent`](`pallet_prelude::ProvideInherent`) implementation to the pallet
///     module under a [`#[pallet::inherent]`](#inherent-palletinherent-optional) attribute
/// 13. rename the usage of `Module` to `Pallet` inside the crate.
/// 14. migration is done, now double check the migration with the checking migration
///     guidelines shown below.
///
/// # Checking upgrade guidelines:
///
/// * compare metadata. Use [subsee](https://github.com/ascjones/subsee) to fetch the metadata
///   and do a diff of the resulting json before and after migration. This checks for:
/// 		* call, names, signature, docs
///     * event names, docs
///     * error names, docs
///     * storage names, hasher, prefixes, default value
///     * error, error, constant
/// * manually check that:
///     * `Origin` was moved inside the macro under
///       [`#[pallet::origin]`](#origin-palletorigin-optional) if it exists
///     * [`ValidateUnsigned`](`pallet_prelude::ValidateUnsigned`) was moved inside the macro
///       under
/// 	  [`#[pallet::validate_unsigned)]`](#validate-unsigned-palletvalidate_unsigned-optional)
/// 	  if it exists
///     * [`ProvideInherent`](`pallet_prelude::ProvideInherent`) was moved inside the macro
///       under [`#[pallet::inherent)]`](#inherent-palletinherent-optional) if it exists
///     * `on_initialize` / `on_finalize` / `on_runtime_upgrade` / `offchain_worker` were moved
///       to the `Hooks` implementation
///     * storages with `config(..)` were converted to `GenesisConfig` field, and their default
///       is `= $expr;` if the storage has a default value
///     * storages with `build($expr)` or `config(..)` were built in `GenesisBuild::build`
///     * `add_extra_genesis` fields were converted to `GenesisConfig` field with their correct
///       default if specified
///     * `add_extra_genesis` build was written into `GenesisBuild::build`
/// * storage items defined with [`pallet`] use the name of the pallet provided by
///   [`traits::PalletInfo::name`] as `pallet_prefix` (in `decl_storage`, storage items used
///   the `pallet_prefix` given as input of `decl_storage` with the syntax `as Example`). Thus
///   a runtime using the pallet must be careful with this change. To handle this change:
///     * either ensure that the name of the pallet given to `construct_runtime!` is the same
///       as the name the pallet was giving to `decl_storage`,
///     * or do a storage migration from the old prefix used to the new prefix used.
///
/// NOTE: The prefixes used by storage items are in metadata. Thus, ensuring the metadata
/// hasn't changed ensures that the `pallet_prefix`s used by the storage items haven't changed.
///
/// # Notes when macro fails to show proper error message spans:
///
/// Rustc loses span for some macro input. Some tips to fix it:
/// * do not use inner attribute:
/// 	```ignore
/// 	#[pallet]
/// 	pub mod pallet {
/// 		//! This inner attribute will make span fail
/// 		..
/// 	}
/// 	```
/// * use the newest nightly possible.
pub use frame_support_procedural::pallet;

/// Contains macro stubs for all of the pallet:: macros
pub mod pallet_macros {
	pub use frame_support_procedural::{
		call_index, compact, config, constant, disable_frame_system_supertrait_check, error, event,
		extra_constants, generate_deposit, generate_storage_info, generate_store, genesis_build,
		genesis_config, getter, hooks, inherent, origin, storage, storage_prefix, storage_version,
		type_value, unbounded, validate_unsigned, weight, whitelist_storage,
	};
}