From cc2b3c986c7c455be31fc2dd95e30726817269b9 Mon Sep 17 00:00:00 2001
From: Egor Suvorov <egor@neon.tech>
Date: Thu, 24 Nov 2022 02:11:06 +0200
Subject: [PATCH] Simplify code: fewer lifetimes, auto-impl VecFrozenVersion

---
 libs/persistent_range_query/src/lib.rs     | 9 +++++++++
 libs/persistent_range_query/src/naive.rs   | 9 ++-------
 libs/persistent_range_query/src/ops/rsq.rs | 2 +-
 3 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/libs/persistent_range_query/src/lib.rs b/libs/persistent_range_query/src/lib.rs
index 48d4f28f15..102755bd21 100644
--- a/libs/persistent_range_query/src/lib.rs
+++ b/libs/persistent_range_query/src/lib.rs
@@ -48,11 +48,20 @@ pub trait VecReadableVersion<Modification: RangeModification<Key>, Key> {
     fn get(&self, keys: Range<Key>) -> Modification::Result;
 }
 
+// TODO: use trait alias when stabilized
 pub trait VecFrozenVersion<Modification: RangeModification<Key>, Key>:
     Clone + VecReadableVersion<Modification, Key>
 {
 }
 
+impl<
+        T: Clone + VecReadableVersion<Modification, Key>,
+        Modification: RangeModification<Key>,
+        Key,
+    > VecFrozenVersion<Modification, Key> for T
+{
+}
+
 pub trait PersistentVecStorage<
     Modification: RangeModification<Key>,
     Initializer: LazyRangeInitializer<Modification::Result, Key>,
diff --git a/libs/persistent_range_query/src/naive.rs b/libs/persistent_range_query/src/naive.rs
index 2e8d7d23ea..d3d1f601ec 100644
--- a/libs/persistent_range_query/src/naive.rs
+++ b/libs/persistent_range_query/src/naive.rs
@@ -1,6 +1,6 @@
 use crate::{
     LazyRangeInitializer, PersistentVecStorage, RangeModification, RangeQueryResult,
-    VecFrozenVersion, VecReadableVersion,
+    VecReadableVersion,
 };
 use std::marker::PhantomData;
 use std::ops::Range;
@@ -42,7 +42,7 @@ impl<Modification: RangeModification<Key>, Key: IndexableKey> VecReadableVersion
 }
 
 // Manual implementation of `Clone` becase `derive` requires `Modification: Clone`
-impl<'a, Modification: RangeModification<Key>, Key: Clone> Clone
+impl<Modification: RangeModification<Key>, Key: Clone> Clone
     for NaiveFrozenVersion<Modification, Key>
 {
     fn clone(&self) -> Self {
@@ -53,11 +53,6 @@ impl<'a, Modification: RangeModification<Key>, Key: Clone> Clone
     }
 }
 
-impl<'a, Modification: RangeModification<Key>, Key: IndexableKey>
-    VecFrozenVersion<Modification, Key> for NaiveFrozenVersion<Modification, Key>
-{
-}
-
 // TODO: is it at all possible to store previous versions in this struct,
 // without any Rc<>?
 pub struct NaiveVecStorage<
diff --git a/libs/persistent_range_query/src/ops/rsq.rs b/libs/persistent_range_query/src/ops/rsq.rs
index a3d6eace93..20cb31289f 100644
--- a/libs/persistent_range_query/src/ops/rsq.rs
+++ b/libs/persistent_range_query/src/ops/rsq.rs
@@ -90,7 +90,7 @@ where
         }
     }
 
-    fn apply<'a>(&self, result: &'a mut SumResult<T>, range: &Range<Key>) {
+    fn apply(&self, result: &mut SumResult<T>, range: &Range<Key>) {
         use AddAssignModification::*;
         match self {
             None => {}