From 3b94b4e86f2238ab0bc6c8b1d2b9dc8802eb5bef Mon Sep 17 00:00:00 2001
From: Alex Orlenko <zxteam@protonmail.com>
Date: Wed, 16 Jun 2021 12:12:42 +0100
Subject: [PATCH] Implement Hash for RegistryKey. Closes #57

---
 src/types.rs   | 15 +++++++++++++++
 tests/tests.rs | 18 ++++++++++++++++++
 2 files changed, 33 insertions(+)

diff --git a/src/types.rs b/src/types.rs
index b66ea8f..6e21af1 100644
--- a/src/types.rs
+++ b/src/types.rs
@@ -1,4 +1,5 @@
 use std::cell::RefCell;
+use std::hash::{Hash, Hasher};
 use std::os::raw::{c_int, c_void};
 use std::sync::{Arc, Mutex};
 use std::{fmt, mem, ptr};
@@ -67,6 +68,20 @@ impl fmt::Debug for RegistryKey {
     }
 }
 
+impl Hash for RegistryKey {
+    fn hash<H: Hasher>(&self, state: &mut H) {
+        self.registry_id.hash(state)
+    }
+}
+
+impl PartialEq for RegistryKey {
+    fn eq(&self, other: &RegistryKey) -> bool {
+        self.registry_id == other.registry_id && Arc::ptr_eq(&self.unref_list, &other.unref_list)
+    }
+}
+
+impl Eq for RegistryKey {}
+
 impl Drop for RegistryKey {
     fn drop(&mut self) {
         let mut unref_list = mlua_expect!(self.unref_list.lock(), "unref list poisoned");
diff --git a/tests/tests.rs b/tests/tests.rs
index 6925a08..6a786ee 100644
--- a/tests/tests.rs
+++ b/tests/tests.rs
@@ -1,3 +1,4 @@
+use std::collections::HashMap;
 use std::iter::FromIterator;
 use std::panic::{catch_unwind, AssertUnwindSafe};
 use std::string::String as StdString;
@@ -797,6 +798,23 @@ fn test_drop_registry_value() -> Result<()> {
     Ok(())
 }
 
+#[test]
+fn test_lua_registry_hash() -> Result<()> {
+    let lua = Lua::new();
+
+    let r1 = Arc::new(lua.create_registry_value("value1")?);
+    let r2 = Arc::new(lua.create_registry_value("value2")?);
+
+    let mut map = HashMap::new();
+    map.insert(r1.clone(), "value1");
+    map.insert(r2.clone(), "value2");
+
+    assert_eq!(map[&r1], "value1");
+    assert_eq!(map[&r2], "value2");
+
+    Ok(())
+}
+
 #[test]
 fn test_lua_registry_ownership() -> Result<()> {
     let lua1 = Lua::new();