From 5fb7658ae9fc9382d8eed71ba58e52227c0976c7 Mon Sep 17 00:00:00 2001
From: Shawn Tabrizi <shawntabrizi@gmail.com>
Date: Tue, 4 May 2021 05:17:52 -0400
Subject: [PATCH] Improve `BoundedVec` API (#8707)
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* improve bounded vec api
* Update frame/support/src/storage/bounded_vec.rs
Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>
* Update frame/support/src/storage/bounded_vec.rs
* Update frame/support/src/storage/bounded_vec.rs
Co-authored-by: Guillaume Thiolliere <gui.thiolliere@gmail.com>
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>
---
.../frame/support/src/storage/bounded_vec.rs | 48 +++++++++++++++++--
1 file changed, 44 insertions(+), 4 deletions(-)
diff --git a/substrate/frame/support/src/storage/bounded_vec.rs b/substrate/frame/support/src/storage/bounded_vec.rs
index 9fcfe403529..5b253f76333 100644
--- a/substrate/frame/support/src/storage/bounded_vec.rs
+++ b/substrate/frame/support/src/storage/bounded_vec.rs
@@ -21,6 +21,7 @@
use sp_std::prelude::*;
use sp_std::{convert::TryFrom, marker::PhantomData};
use codec::{FullCodec, Encode, EncodeLike, Decode};
+use core::{ops::{Index, IndexMut}, slice::SliceIndex};
use crate::{
traits::Get,
storage::{generator, StorageDecodeLength, StorageValue, StorageMap, StorageDoubleMap},
@@ -179,6 +180,18 @@ impl<T: BoundedVecValue, S: Get<u32>> AsRef<Vec<T>> for BoundedVec<T, S> {
}
}
+impl<T: BoundedVecValue, S: Get<u32>> AsRef<[T]> for BoundedVec<T, S> {
+ fn as_ref(&self) -> &[T] {
+ &self.0
+ }
+}
+
+impl<T: BoundedVecValue, S: Get<u32>> AsMut<[T]> for BoundedVec<T, S> {
+ fn as_mut(&mut self) -> &mut [T] {
+ &mut self.0
+ }
+}
+
// will allow for immutable all operations of `Vec<T>` on `BoundedVec<T>`.
impl<T: BoundedVecValue, S: Get<u32>> sp_std::ops::Deref for BoundedVec<T, S> {
type Target = Vec<T>;
@@ -189,10 +202,19 @@ impl<T: BoundedVecValue, S: Get<u32>> sp_std::ops::Deref for BoundedVec<T, S> {
}
// Allows for indexing similar to a normal `Vec`. Can panic if out of bound.
-impl<T: BoundedVecValue, S: Get<u32>> sp_std::ops::Index<usize> for BoundedVec<T, S> {
- type Output = T;
- fn index(&self, index: usize) -> &Self::Output {
- self.get(index).expect("index out of bound")
+impl<T: BoundedVecValue, S: Get<u32>, I: SliceIndex<[T]>> Index<I> for BoundedVec<T, S> {
+ type Output = I::Output;
+
+ #[inline]
+ fn index(&self, index: I) -> &Self::Output {
+ self.0.index(index)
+ }
+}
+
+impl<T: BoundedVecValue, S: Get<u32>, I: SliceIndex<[T]>> IndexMut<I> for BoundedVec<T, S> {
+ #[inline]
+ fn index_mut(&mut self, index: I) -> &mut Self::Output {
+ self.0.index_mut(index)
}
}
@@ -212,6 +234,12 @@ impl<T: BoundedVecValue, S: Get<u32>> codec::DecodeLength for BoundedVec<T, S> {
}
}
+impl<T: BoundedVecValue + PartialEq, S: Get<u32>> PartialEq<Vec<T>> for BoundedVec<T, S> {
+ fn eq(&self, other: &Vec<T>) -> bool {
+ &self.0 == other
+ }
+}
+
impl<T: BoundedVecValue, S: Get<u32>> StorageDecodeLength for BoundedVec<T, S> {}
/// Storage value that is *maybe* capable of [`StorageAppend`](crate::storage::StorageAppend).
@@ -467,4 +495,16 @@ pub mod test {
assert_eq!(bounded.len(), 7);
assert!(bounded.try_mutate(|v| v.push(8)).is_none());
}
+
+ #[test]
+ fn slice_indexing_works() {
+ let bounded: BoundedVec<u32, Seven> = vec![1, 2, 3, 4, 5, 6].try_into().unwrap();
+ assert_eq!(&bounded[0..=2], &[1, 2, 3]);
+ }
+
+ #[test]
+ fn vec_eq_works() {
+ let bounded: BoundedVec<u32, Seven> = vec![1, 2, 3, 4, 5, 6].try_into().unwrap();
+ assert_eq!(bounded, vec![1, 2, 3, 4, 5, 6]);
+ }
}
--
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