feat: serde feature

Cargo.toml

@@ -8,13 +8,14 @@ license = "Apache-2.0/MIT"
 repository = "https://github.com/antouhou/rs-merkle"
 documentation = "https://docs.rs/rs_merkle/"
 readme = "README.md"
-keywords = ["merkle", "tree", "proof", "hash", "multiproof",]
+keywords = ["merkle", "tree", "proof", "hash", "multiproof"]
 exclude = ["/ci/*", "/scripts/*", "/.github/*", "/bors.toml"]
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
 sha2 = { version = "0.10", default-features = false }
+serde = { version = "1", optional = true, features = ["derive"] }
 
 # standard crate data is left out
 [dev-dependencies]
@@ -23,3 +24,4 @@ rayon = "1.5.1"
 [features]
 default = ['std']
 std = ["sha2/std"]
+serde = ["dep:serde"]

src/merkle_proof.rs

@@ -47,6 +47,7 @@ use core::convert::TryFrom;
 ///
 /// [`Hasher`]: crate::Hasher
 /// [`algorithms::Sha256`]: crate::algorithms::Sha256
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub struct MerkleProof<H> {
     proof_hashes: Vec<H>,
 }

src/merkle_tree.rs

@@ -15,6 +15,7 @@ use crate::{
 /// roll back to any previously committed state of the tree. This scenario is similar to Git and
 /// can be found in databases and file systems.
 #[derive(Clone)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub struct MerkleTree<H> {
     current_working_tree: PartialTree<H>,
     history: Vec<PartialTree<H>>,

src/partial_tree.rs

@@ -12,6 +12,7 @@ type PartialTreeLayer<H> = Vec<(usize, H)>;
 /// [`MerkleTree`]: crate::MerkleTree
 /// [`MerkleProof`]: crate::MerkleProof
 #[derive(Clone)]
+#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
 pub struct PartialTree<H> {
     layers: Vec<Vec<(usize, H)>>,
 }