Ranked Collective pallet (#11548)

* Ranked Collective pallet

* Fixes

* benchmarks

* Weights

* Allow class voting in rank
Use bare ayes for calculating support.
Allow only promotion/demotion by one rank only.
Allow removal of member with rank zero only.
Use new Tally API

* Index by rank, still O(1).

* Custom vote weights

* Formatting

* Update frame/ranked-collective/src/lib.rs

* Broken :(

* origin guard; cleanup uses new API

* Formatting

* Promote/demote by rank

* Formatting

* Use new API

* Remove code in another PR

* Remove code in another PR

* Formatting

* Remove code in another PR

* Docs

* Docs

* Bump

* Fixes

* Formatting

* Fixes

substrate/frame/support/src/storage/bounded_vec.rs

@@ -286,6 +286,12 @@ impl<T, S: Get<u32>> BoundedVec<T, S> {
 		Self::with_bounded_capacity(Self::bound())
 	}
 
+	/// Consume and truncate the vector `v` in order to create a new instance of `Self` from it.
+	pub fn truncate_from(mut v: Vec<T>) -> Self {
+		v.truncate(Self::bound());
+		Self::unchecked_from(v)
+	}
+
 	/// Get the bound of the type in `usize`.
 	pub fn bound() -> usize {
 		S::get() as usize

substrate/frame/support/src/storage/mod.rs

@@ -27,7 +27,7 @@ use crate::{
 use codec::{Decode, Encode, EncodeLike, FullCodec, FullEncode};
 use sp_core::storage::ChildInfo;
 use sp_runtime::generic::{Digest, DigestItem};
-use sp_std::prelude::*;
+use sp_std::{marker::PhantomData, prelude::*};
 
 pub use self::{
 	transactional::{
@@ -51,6 +51,10 @@ pub mod types;
 pub mod unhashed;
 pub mod weak_bounded_vec;
 
+/// Utility type for converting a storage map into a `Get<u32>` impl which returns the maximum
+/// key size.
+pub struct KeyLenOf<M>(PhantomData<M>);
+
 /// A trait for working with macro-generated storage values under the substrate storage API.
 ///
 /// Details on implementation can be found at [`generator::StorageValue`].

substrate/frame/support/src/storage/types/double_map.rs

@@ -22,7 +22,7 @@ use crate::{
 	metadata::{StorageEntryMetadata, StorageEntryType},
 	storage::{
 		types::{OptionQuery, QueryKindTrait, StorageEntryMetadataBuilder},
-		StorageAppend, StorageDecodeLength, StoragePrefixedMap, StorageTryAppend,
+		KeyLenOf, StorageAppend, StorageDecodeLength, StoragePrefixedMap, StorageTryAppend,
 	},
 	traits::{Get, GetDefault, StorageInfo, StorageInstance},
 };
@@ -70,6 +70,35 @@ pub struct StorageDoubleMap<
 	)>,
 );
 
+impl<Prefix, Hasher1, Key1, Hasher2, Key2, Value, QueryKind, OnEmpty, MaxValues> Get<u32>
+	for KeyLenOf<
+		StorageDoubleMap<
+			Prefix,
+			Hasher1,
+			Key1,
+			Hasher2,
+			Key2,
+			Value,
+			QueryKind,
+			OnEmpty,
+			MaxValues,
+		>,
+	> where
+	Prefix: StorageInstance,
+	Hasher1: crate::hash::StorageHasher,
+	Hasher2: crate::hash::StorageHasher,
+	Key1: MaxEncodedLen,
+	Key2: MaxEncodedLen,
+{
+	fn get() -> u32 {
+		let z = Hasher1::max_len::<Key1>() +
+			Hasher2::max_len::<Key2>() +
+			Prefix::pallet_prefix().len() +
+			Prefix::STORAGE_PREFIX.len();
+		z as u32
+	}
+}
+
 impl<Prefix, Hasher1, Key1, Hasher2, Key2, Value, QueryKind, OnEmpty, MaxValues>
 	crate::storage::generator::StorageDoubleMap<Key1, Key2, Value>
 	for StorageDoubleMap<Prefix, Hasher1, Key1, Hasher2, Key2, Value, QueryKind, OnEmpty, MaxValues>

substrate/frame/support/src/storage/types/map.rs

@@ -22,7 +22,7 @@ use crate::{
 	metadata::{StorageEntryMetadata, StorageEntryType},
 	storage::{
 		types::{OptionQuery, QueryKindTrait, StorageEntryMetadataBuilder},
-		StorageAppend, StorageDecodeLength, StoragePrefixedMap, StorageTryAppend,
+		KeyLenOf, StorageAppend, StorageDecodeLength, StoragePrefixedMap, StorageTryAppend,
 	},
 	traits::{Get, GetDefault, StorageInfo, StorageInstance},
 };
@@ -53,6 +53,20 @@ pub struct StorageMap<
 	MaxValues = GetDefault,
 >(core::marker::PhantomData<(Prefix, Hasher, Key, Value, QueryKind, OnEmpty, MaxValues)>);
 
+impl<Prefix, Hasher, Key, Value, QueryKind, OnEmpty, MaxValues> Get<u32>
+	for KeyLenOf<StorageMap<Prefix, Hasher, Key, Value, QueryKind, OnEmpty, MaxValues>>
+where
+	Prefix: StorageInstance,
+	Hasher: crate::hash::StorageHasher,
+	Key: FullCodec + MaxEncodedLen,
+{
+	fn get() -> u32 {
+		let z =
+			Hasher::max_len::<Key>() + Prefix::pallet_prefix().len() + Prefix::STORAGE_PREFIX.len();
+		z as u32
+	}
+}
+
 impl<Prefix, Hasher, Key, Value, QueryKind, OnEmpty, MaxValues>
 	crate::storage::generator::StorageMap<Key, Value>
 	for StorageMap<Prefix, Hasher, Key, Value, QueryKind, OnEmpty, MaxValues>