Feature: Add an in-memory wallet backend framework

Cargo.toml

@@ -17,7 +17,7 @@ members = [
 
 [workspace.package]
 edition = "2021"
-rust-version = "1.65"
+rust-version = "1.69"
 repository = "https://github.com/zcash/librustzcash"
 license = "MIT OR Apache-2.0"
 categories = ["cryptography::cryptocurrencies"]

components/zcash_protocol/src/lib.rs

@@ -25,7 +25,7 @@ pub mod memo;
 pub mod value;
 
 /// A Zcash shielded transfer protocol.
-#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub enum ShieldedProtocol {
     /// The Sapling protocol
     Sapling,
@@ -34,7 +34,7 @@ pub enum ShieldedProtocol {
 }
 
 /// A value pool in the Zcash protocol.
-#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
 pub enum PoolType {
     /// The transparent value pool
     Transparent,

components/zcash_protocol/src/memo.rs

@@ -144,9 +144,10 @@ impl Deref for TextMemo {
 }
 
 /// An unencrypted memo received alongside a shielded note in a Zcash transaction.
-#[derive(Clone)]
+#[derive(Clone, Default)]
 pub enum Memo {
     /// An empty memo field.
+    #[default]
     Empty,
     /// A memo field containing a UTF-8 string.
     Text(TextMemo),
@@ -171,12 +172,6 @@ impl fmt::Debug for Memo {
     }
 }
 
-impl Default for Memo {
-    fn default() -> Self {
-        Memo::Empty
-    }
-}
-
 impl PartialEq for Memo {
     fn eq(&self, rhs: &Memo) -> bool {
         match (self, rhs) {

rust-toolchain.toml

@@ -1,3 +1,3 @@
 [toolchain]
-channel = "1.65.0"
+channel = "1.69.0"
 components = [ "clippy", "rustfmt" ]

zcash_client_backend/src/data_api.rs

@@ -107,6 +107,9 @@ pub mod error;
 pub mod scanning;
 pub mod wallet;
 
+#[cfg(any(test, feature = "test-dependencies"))]
+pub mod mem_wallet;
+
 /// The height of subtree roots in the Sapling note commitment tree.
 ///
 /// This conforms to the structure of subtree data returned by