Per-things trait. (#4904)

* Give perthigns the trait it always deserved.

* Make staking and phragmen work with the new generic per_thing

* Make everything work together 🔨

* a bit of cleanup

* Clean usage

* Bump.

* Fix name

* fix grumbles

* hopefully fix the ui test

* Some grumbles

* revamp traits again

* Better naming again.

substrate/client/src/cht.rs

@@ -28,7 +28,7 @@ use codec::Encode;
 use sp_trie;
 
 use sp_core::{H256, convert_hash};
-use sp_runtime::traits::{Header as HeaderT, SimpleArithmetic, Zero, One};
+use sp_runtime::traits::{Header as HeaderT, AtLeast32Bit, Zero, One};
 use sp_state_machine::{
 	MemoryDB, TrieBackend, Backend as StateBackend, StorageProof, InMemoryBackend,
 	prove_read_on_trie_backend, read_proof_check, read_proof_check_on_proving_backend
@@ -48,7 +48,7 @@ pub fn size<N: From<u32>>() -> N {
 /// Returns Some(cht_number) if CHT is need to be built when the block with given number is canonized.
 pub fn is_build_required<N>(cht_size: N, block_num: N) -> Option<N>
 	where
-		N: Clone + SimpleArithmetic,
+		N: Clone + AtLeast32Bit,
 {
 	let block_cht_num = block_to_cht_number(cht_size.clone(), block_num.clone())?;
 	let two = N::one() + N::one();
@@ -66,7 +66,7 @@ pub fn is_build_required<N>(cht_size: N, block_num: N) -> Option<N>
 /// Returns Some(max_cht_number) if CHT has ever been built given maximal canonical block number.
 pub fn max_cht_number<N>(cht_size: N, max_canonical_block: N) -> Option<N>
 	where
-		N: Clone + SimpleArithmetic,
+		N: Clone + AtLeast32Bit,
 {
 	let max_cht_number = block_to_cht_number(cht_size, max_canonical_block)?;
 	let two = N::one() + N::one();
@@ -291,18 +291,18 @@ fn build_pairs<Header, I>(
 /// More generally: CHT N includes block (1 + N*SIZE)...((N+1)*SIZE).
 /// This is because the genesis hash is assumed to be known
 /// and including it would be redundant.
-pub fn start_number<N: SimpleArithmetic>(cht_size: N, cht_num: N) -> N {
+pub fn start_number<N: AtLeast32Bit>(cht_size: N, cht_num: N) -> N {
 	(cht_num * cht_size) + N::one()
 }
 
 /// Get the ending block of a given CHT.
-pub fn end_number<N: SimpleArithmetic>(cht_size: N, cht_num: N) -> N {
+pub fn end_number<N: AtLeast32Bit>(cht_size: N, cht_num: N) -> N {
 	(cht_num + N::one()) * cht_size
 }
 
 /// Convert a block number to a CHT number.
 /// Returns `None` for `block_num` == 0, `Some` otherwise.
-pub fn block_to_cht_number<N: SimpleArithmetic>(cht_size: N, block_num: N) -> Option<N> {
+pub fn block_to_cht_number<N: AtLeast32Bit>(cht_size: N, block_num: N) -> Option<N> {
 	if block_num == N::zero() {
 		None
 	} else {

substrate/client/src/leaves.rs

@@ -19,7 +19,7 @@
 use std::collections::BTreeMap;
 use std::cmp::Reverse;
 use kvdb::{KeyValueDB, DBTransaction};
-use sp_runtime::traits::SimpleArithmetic;
+use sp_runtime::traits::AtLeast32Bit;
 use codec::{Encode, Decode};
 use sp_blockchain::{Error, Result};
 
@@ -65,7 +65,7 @@ pub struct LeafSet<H, N> {
 
 impl<H, N> LeafSet<H, N> where
 	H: Clone + PartialEq + Decode + Encode,
-	N: std::fmt::Debug + Clone + SimpleArithmetic + Decode + Encode,
+	N: std::fmt::Debug + Clone + AtLeast32Bit + Decode + Encode,
 {
 	/// Construct a new, blank leaf set.
 	pub fn new() -> Self {
@@ -251,7 +251,7 @@ pub struct Undo<'a, H: 'a, N: 'a> {
 
 impl<'a, H: 'a, N: 'a> Undo<'a, H, N> where
 	H: Clone + PartialEq + Decode + Encode,
-	N: std::fmt::Debug + Clone + SimpleArithmetic + Decode + Encode,
+	N: std::fmt::Debug + Clone + AtLeast32Bit + Decode + Encode,
 {
 	/// Undo an imported block by providing the displaced leaf.
 	pub fn undo_import(&mut self, displaced: ImportDisplaced<H, N>) {

substrate/client/src/light/fetcher.rs

@@ -25,7 +25,7 @@ use codec::{Decode, Encode};
 use sp_core::{convert_hash, traits::CodeExecutor};
 use sp_runtime::traits::{
 	Block as BlockT, Header as HeaderT, Hash, HashFor, NumberFor,
-	SimpleArithmetic, CheckedConversion,
+	AtLeast32Bit, CheckedConversion,
 };
 use sp_state_machine::{
 	ChangesTrieRootsStorage, ChangesTrieAnchorBlockId, ChangesTrieConfigurationRange,
@@ -286,7 +286,7 @@ impl<E, Block, H, S> FetchChecker<Block> for LightDataChecker<E, H, Block, S>
 }
 
 /// A view of BTreeMap<Number, Hash> as a changes trie roots storage.
-struct RootsStorage<'a, Number: SimpleArithmetic, Hash: 'a> {
+struct RootsStorage<'a, Number: AtLeast32Bit, Hash: 'a> {
 	roots: (Number, &'a [Hash]),
 	prev_roots: &'a BTreeMap<Number, Hash>,
 }
@@ -294,7 +294,7 @@ struct RootsStorage<'a, Number: SimpleArithmetic, Hash: 'a> {
 impl<'a, H, Number, Hash> ChangesTrieRootsStorage<H, Number> for RootsStorage<'a, Number, Hash>
 	where
 		H: Hasher,
-		Number: ::std::fmt::Display + ::std::hash::Hash + Clone + SimpleArithmetic + Encode + Decode + Send + Sync + 'static,
+		Number: ::std::fmt::Display + ::std::hash::Hash + Clone + AtLeast32Bit + Encode + Decode + Send + Sync + 'static,
 		Hash: 'a + Send + Sync + Clone + AsRef<[u8]>,
 {
 	fn build_anchor(