From 90702ae3d05b980d4cc6aefc61adcf8e53172658 Mon Sep 17 00:00:00 2001
From: Simon Jakobi <simon.jakobi@gmail.com>
Date: Wed, 26 Nov 2025 21:04:39 +0100
Subject: [PATCH] Relax constraints on Semigroup and Monoid instances

---
 Data/HashMap/Internal.hs | 4 ++--
 Data/HashSet/Internal.hs | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/Data/HashMap/Internal.hs b/Data/HashMap/Internal.hs
index 8dc71452..a9ca4457 100644
--- a/Data/HashMap/Internal.hs
+++ b/Data/HashMap/Internal.hs
@@ -311,7 +311,7 @@ instance Bifoldable HashMap where
 --
 -- >>> fromList [(1,'a'),(2,'b')] <> fromList [(2,'c'),(3,'d')]
 -- fromList [(1,'a'),(2,'b'),(3,'d')]
-instance Hashable k => Semigroup (HashMap k v) where
+instance Eq k => Semigroup (HashMap k v) where
   (<>) = union
   {-# INLINE (<>) #-}
   stimes = stimesIdempotentMonoid
@@ -327,7 +327,7 @@ instance Hashable k => Semigroup (HashMap k v) where
 --
 -- >>> mappend (fromList [(1,'a'),(2,'b')]) (fromList [(2,'c'),(3,'d')])
 -- fromList [(1,'a'),(2,'b'),(3,'d')]
-instance Hashable k => Monoid (HashMap k v) where
+instance Eq k => Monoid (HashMap k v) where
   mempty = empty
   {-# INLINE mempty #-}
   mappend = (<>)
diff --git a/Data/HashSet/Internal.hs b/Data/HashSet/Internal.hs
index aa0e2fbf..6f62b39d 100644
--- a/Data/HashSet/Internal.hs
+++ b/Data/HashSet/Internal.hs
@@ -187,7 +187,7 @@ instance Foldable.Foldable HashSet where
 --
 -- >>> fromList [1,2] <> fromList [2,3]
 -- fromList [1,2,3]
-instance Hashable a => Semigroup (HashSet a) where
+instance Eq a => Semigroup (HashSet a) where
     (<>) = union
     {-# INLINE (<>) #-}
     stimes = stimesIdempotentMonoid
@@ -206,7 +206,7 @@ instance Hashable a => Semigroup (HashSet a) where
 --
 -- >>> mappend (fromList [1,2]) (fromList [2,3])
 -- fromList [1,2,3]
-instance Hashable a => Monoid (HashSet a) where
+instance Eq a => Monoid (HashSet a) where
     mempty = empty
     {-# INLINE mempty #-}
     mappend = (<>)