Drop MemoHash's std Hash impl and route cache-identity hashing through CacheHash (#4209)

node-graph/libraries/core-types/src/memo.rs

@@ -11,12 +11,34 @@ pub struct IORecord<I, O> {
 	pub output: O,
 }
 
-#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Debug)]
+#[derive(Clone, Debug)]
 pub struct MemoHash<T: CacheHash> {
 	hash: u64,
 	value: Arc<T>,
 }
 
+// Compare the value, not the cache `hash`: `CacheHash` is not guaranteed to be an equivalence relation,
+// so it can't back `eq`/`cmp`. Cache-identity hashing goes through `CacheHash`.
+impl<T: CacheHash + PartialEq> PartialEq for MemoHash<T> {
+	fn eq(&self, other: &Self) -> bool {
+		self.value == other.value
+	}
+}
+
+impl<T: CacheHash + Eq> Eq for MemoHash<T> {}
+
+impl<T: CacheHash + PartialOrd> PartialOrd for MemoHash<T> {
+	fn partial_cmp(&self, other: &Self) -> Option<core::cmp::Ordering> {
+		self.value.partial_cmp(&other.value)
+	}
+}
+
+impl<T: CacheHash + Ord> Ord for MemoHash<T> {
+	fn cmp(&self, other: &Self) -> core::cmp::Ordering {
+		self.value.cmp(&other.value)
+	}
+}
+
 impl<'de, T: serde::Deserialize<'de> + CacheHash> serde::Deserialize<'de> for MemoHash<T> {
 	fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
 	where
@@ -67,12 +89,6 @@ impl<T: CacheHash> From<T> for MemoHash<T> {
 	}
 }
 
-impl<T: CacheHash> Hash for MemoHash<T> {
-	fn hash<H: Hasher>(&self, state: &mut H) {
-		self.hash.hash(state)
-	}
-}
-
 impl<T: CacheHash> CacheHash for MemoHash<T> {
 	fn cache_hash<H: Hasher>(&self, state: &mut H) {
 		self.hash.hash(state);

node-graph/libraries/core-types/src/transform.rs

@@ -31,7 +31,7 @@ pub trait Transform {
 	/// - `skew`: the horizontal shear coefficient (the raw matrix value, not an angle)
 	///
 	/// The original transform can be reconstructed as:
-	/// ```
+	/// ```ignore
 	/// DAffine2::from_scale_angle_translation(scale, rotation, translation) * DAffine2::from_cols_array(&[1., 0., skew, 1., 0., 0.])
 	/// ```
 	#[inline(always)]