Fix invalid trait implementations (#96)

* Fix invalid trait implementations

* Simplify with derive_where

Cargo.toml

@@ -39,6 +39,7 @@ bincode = "1.3.3"
 bytemuck = "1.18"
 color-eyre = "0.6"
 criterion = { version = "0.5", features = ["async_tokio", "html_reports"] }
+derive-where = "1"
 ethabi = "18.0.0"
 ethers-core = { git = "https://github.com/gakonst/ethers-rs", default-features = false }
 hex = "0.4.0"

crates/trees/Cargo.toml

@@ -14,6 +14,7 @@ storage.workspace = true
 # 3rd Party
 bytemuck.workspace = true
 color-eyre.workspace = true
+derive-where.workspace = true
 hex.workspace = true
 hex-literal.workspace = true
 itertools.workspace = true

crates/trees/src/cascading/mod.rs

@@ -2,6 +2,7 @@ use std::fmt::Debug;
 
 use bytemuck::Pod;
 use color_eyre::eyre::{ensure, Result};
+use derive_where::derive_where;
 use hasher::Hasher;
 
 use crate::proof::{Branch, Proof};
@@ -33,7 +34,10 @@ use self::storage_ops::{sparse_fill_partial_subtree, StorageOps};
 /// Leaves are 0 indexed
 /// 0  1  2  3  4  5  6  7
 /// ```
-#[derive(Debug, Clone, PartialEq, Eq)]
+#[derive_where(Clone; <H as Hasher>::Hash: Clone, S: Clone)]
+#[derive_where(PartialEq; <H as Hasher>::Hash: PartialEq, S: PartialEq)]
+#[derive_where(Eq; <H as Hasher>::Hash: Eq, S: Eq)]
+#[derive_where(Debug; <H as Hasher>::Hash: Debug, S: Debug)]
 pub struct CascadingMerkleTree<H, S = Vec<<H as Hasher>::Hash>>
 where
     H: Hasher,
@@ -477,7 +481,7 @@ mod tests {
 
     pub fn debug_tree<H, S>(tree: &CascadingMerkleTree<H, S>)
     where
-        H: Hasher + std::fmt::Debug,
+        H: Hasher,
         <H as Hasher>::Hash: Debug + Copy,
         S: GenericStorage<H::Hash> + std::fmt::Debug,
     {
@@ -487,7 +491,7 @@ mod tests {
 
     pub fn debug_storage<H, S>(storage: &S)
     where
-        H: Hasher + std::fmt::Debug,
+        H: Hasher,
         <H as Hasher>::Hash: Debug + Copy,
         S: std::ops::Deref<Target = [<H as Hasher>::Hash]> + std::fmt::Debug,
     {

crates/trees/src/imt/mod.rs

@@ -4,12 +4,16 @@ use std::fmt::Debug;
 use std::iter::{once, repeat, successors};
 
 use bytemuck::Pod;
+use derive_where::derive_where;
 use hasher::Hasher;
 
 use crate::proof::{Branch, Proof};
 
 /// Merkle tree with all leaf and intermediate hashes stored
-#[derive(Clone, PartialEq, Eq, Debug)]
+#[derive_where(Clone; <H as Hasher>::Hash: Clone)]
+#[derive_where(PartialEq; <H as Hasher>::Hash: PartialEq)]
+#[derive_where(Eq; <H as Hasher>::Hash: Eq)]
+#[derive_where(Debug; <H as Hasher>::Hash: Debug)]
 pub struct MerkleTree<H>
 where
     H: Hasher,

crates/trees/src/proof.rs

@@ -1,31 +1,18 @@
 use std::fmt::Debug;
 
+use derive_where::derive_where;
 use hasher::Hasher;
 use serde::{Deserialize, Serialize};
 
 /// Merkle proof path, bottom to top.
-#[derive(Clone)]
+#[derive_where(Clone; <H as Hasher>::Hash: Clone)]
+#[derive_where(PartialEq; <H as Hasher>::Hash: PartialEq)]
+#[derive_where(Eq; <H as Hasher>::Hash: Eq)]
+#[derive_where(Debug; <H as Hasher>::Hash: Debug)]
 pub struct Proof<H>(pub Vec<Branch<H::Hash>>)
 where
     H: Hasher;
 
-impl<H> PartialEq for Proof<H>
-where
-    H: Hasher,
-    H::Hash: PartialEq,
-{
-    fn eq(&self, other: &Self) -> bool {
-        self.0 == other.0
-    }
-}
-
-impl<H> Eq for Proof<H>
-where
-    H: Hasher,
-    H::Hash: Eq,
-{
-}
-
 /// Element of a Merkle proof
 #[derive(Clone, Copy, PartialEq, Eq, Serialize, Deserialize)]
 pub enum Branch<T> {
@@ -82,13 +69,3 @@ impl<T: Debug> Debug for Branch<T> {
         }
     }
 }
-
-impl<H> Debug for Proof<H>
-where
-    H: Hasher,
-    H::Hash: Debug,
-{
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        f.debug_tuple("Proof").field(&self.0).finish()
-    }
-}