From adc542fd219ed17a14cc175dea00ae1a2632cf73 Mon Sep 17 00:00:00 2001
From: George Thomas <georgefsthomas@gmail.com>
Date: Wed, 25 Mar 2026 01:01:22 +0000
Subject: [PATCH] Pass all non-primitive types by (immutable) reference

---
 lib/GarnetRs/Wrapped.hs | 6 +++---
 rust/lib.rs             | 8 ++++----
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/lib/GarnetRs/Wrapped.hs b/lib/GarnetRs/Wrapped.hs
index 51d9255..b6b7c9c 100644
--- a/lib/GarnetRs/Wrapped.hs
+++ b/lib/GarnetRs/Wrapped.hs
@@ -57,13 +57,13 @@ hello :: ByteString -> IO ()
 hello s = useAsCString s $ Raw.hello . unsafeFromPtr
 
 helloStruct :: T -> IO ()
-helloStruct = Raw.hello_struct . convertT
+helloStruct = flip with (Raw.hello_struct . unsafeFromPtr) . convertT
 
 helloShape :: Shape -> IO ()
-helloShape = Raw.hello_shape . convertShape
+helloShape = flip with (Raw.hello_shape . unsafeFromPtr) . convertShape
 
 add :: Int64 -> Int64 -> Int64
 add = Raw.add
 
 sumTree :: BTree Int64 -> Int64
-sumTree = unsafePerformIO . flip withBTree Raw.sum_tree
+sumTree = unsafePerformIO . flip withBTree (flip with $ Raw.sum_tree . unsafeFromPtr)
diff --git a/rust/lib.rs b/rust/lib.rs
index 35b3ba2..d80313d 100644
--- a/rust/lib.rs
+++ b/rust/lib.rs
@@ -22,7 +22,7 @@ struct T {
 }
 
 #[unsafe(no_mangle)]
-extern "C" fn hello_struct(t: T) -> () {
+extern "C" fn hello_struct(t: &T) -> () {
     say_hello(&format!("{:?}", t))
 }
 
@@ -34,7 +34,7 @@ enum Shape {
 }
 
 #[unsafe(no_mangle)]
-extern "C" fn hello_shape(s: Shape) -> () {
+extern "C" fn hello_shape(s: &Shape) -> () {
     say_hello(&format!("{:?}", s))
 }
 
@@ -78,6 +78,6 @@ enum BTreeC {
 }
 
 #[unsafe(no_mangle)]
-extern "C" fn sum_tree(t: BTreeC) -> i64 {
-    (unsafe { std::mem::transmute::<_, &BTree<i64>>(&t) }).sum()
+extern "C" fn sum_tree(t: &BTreeC) -> i64 {
+    (unsafe { std::mem::transmute::<_, &BTree<i64>>(t) }).sum()
 }