From 908070947406dd942ada377278c26715077187e2 Mon Sep 17 00:00:00 2001
From: Lucian Popescu <lucian.popescu@tecnico.ulisboa.pt>
Date: Wed, 24 Jun 2026 15:38:31 +0100
Subject: [PATCH] Add ByteRepr for enums

---
 cpp2rust/converter/converter.cpp              |  3 ++
 cpp2rust/converter/converter.h                |  2 +
 .../converter/models/converter_refcount.cpp   | 17 ++++--
 .../converter/models/converter_refcount.h     |  2 +
 .../refcount/cross_tu_anon_enum_collision.rs  | 16 ++++++
 .../out/refcount/cross_tu_tag_collision.rs    |  8 +++
 .../ub/out/refcount/enum_out_of_range_cast.rs |  8 +++
 .../refcount/enum_out_of_range_increment.rs   |  8 +++
 tests/unit/out/refcount/anonymous_enum.rs     | 53 ++++++++++++++++++-
 tests/unit/out/refcount/anonymous_enum_c.rs   | 53 ++++++++++++++++++-
 .../unit/out/refcount/bool_condition_enum.rs  |  8 +++
 .../out/refcount/bool_condition_enum_c.rs     |  8 +++
 .../out/refcount/bool_condition_logical.rs    |  8 +++
 .../out/refcount/bool_condition_logical_c.rs  |  8 +++
 tests/unit/out/refcount/c_struct.rs           |  8 +++
 .../out/refcount/enum_default_in_static.rs    | 21 +++++++-
 tests/unit/out/refcount/enum_increment.rs     |  8 +++
 tests/unit/out/refcount/enum_int_interop.rs   | 24 +++++++++
 tests/unit/out/refcount/enum_int_interop_c.rs | 24 +++++++++
 tests/unit/out/refcount/switch_char.rs        |  8 +++
 tests/unit/out/refcount/switch_enum.rs        |  8 +++
 .../out/refcount/va_arg_non_primitive_ptrs.rs |  8 +++
 22 files changed, 304 insertions(+), 7 deletions(-)

diff --git a/cpp2rust/converter/converter.cpp b/cpp2rust/converter/converter.cpp
index 131cb7ed..09e9d526 100644
--- a/cpp2rust/converter/converter.cpp
+++ b/cpp2rust/converter/converter.cpp
@@ -3154,6 +3154,7 @@ bool Converter::VisitEnumDecl(clang::EnumDecl *decl) {
 
   AddFromImpl(decl);
   AddIncDecImpls(decl);
+  AddByteReprTrait(decl);
   return false;
 }
 
@@ -3936,6 +3937,8 @@ void Converter::EmitDefaultStructLiteral(const clang::RecordDecl *decl) {
 
 void Converter::AddByteReprTrait(const clang::RecordDecl *decl) {}
 
+void Converter::AddByteReprTrait(const clang::EnumDecl *decl) {}
+
 void Converter::ConvertUnsignedArithBinaryOperator(clang::BinaryOperator *op,
                                                    clang::Expr *expr) {
   StrCat(token::kDot);
diff --git a/cpp2rust/converter/converter.h b/cpp2rust/converter/converter.h
index 63de20e4..735b118e 100644
--- a/cpp2rust/converter/converter.h
+++ b/cpp2rust/converter/converter.h
@@ -539,6 +539,8 @@ class Converter : public clang::RecursiveASTVisitor<Converter> {
 
   virtual void AddByteReprTrait(const clang::RecordDecl *decl);
 
+  virtual void AddByteReprTrait(const clang::EnumDecl *decl);
+
   virtual void
   ConvertUnsignedArithBinaryOperator(clang::BinaryOperator *binary_operator,
                                      clang::Expr *expr);
diff --git a/cpp2rust/converter/models/converter_refcount.cpp b/cpp2rust/converter/models/converter_refcount.cpp
index 6dedd871..17b4f149 100644
--- a/cpp2rust/converter/models/converter_refcount.cpp
+++ b/cpp2rust/converter/models/converter_refcount.cpp
@@ -510,10 +510,8 @@ static bool recordImplementsByteRepr(const clang::RecordDecl *decl) {
   // fields.
   for (auto *f : decl->fields()) {
     auto qt = f->getType();
-    if (qt->isEnumeralType()) {
-      return false;
-    }
-    if (!qt->isIntegerType() && !qt->isFloatingType()) {
+    if (!qt->isIntegerType() && !qt->isFloatingType() &&
+        !qt->isEnumeralType()) {
       return false;
     }
   }
@@ -567,6 +565,17 @@ void ConverterRefCount::AddByteReprTrait(const clang::RecordDecl *decl) {
   }
 }
 
+void ConverterRefCount::AddByteReprTrait(const clang::EnumDecl *decl) {
+  auto name = GetRecordName(decl);
+  StrCat(std::format("impl ByteRepr for {}", name));
+  PushBrace impl_brace(*this);
+  StrCat(
+      "fn to_bytes(&self, buf: &mut [u8]) { (*self as i32).to_bytes(buf); }");
+  StrCat(std::format("fn from_bytes(buf: &[u8]) -> Self {{ "
+                     "<{}>::from(i32::from_bytes(buf)) }}",
+                     name));
+}
+
 std::string
 ConverterRefCount::GetSelfMaybeWithMut(const clang::CXXMethodDecl *decl) {
   return "&self";
diff --git a/cpp2rust/converter/models/converter_refcount.h b/cpp2rust/converter/models/converter_refcount.h
index 491c5222..122a930d 100644
--- a/cpp2rust/converter/models/converter_refcount.h
+++ b/cpp2rust/converter/models/converter_refcount.h
@@ -39,6 +39,8 @@ class ConverterRefCount final : public Converter {
 
   void AddByteReprTrait(const clang::RecordDecl *decl) override;
 
+  void AddByteReprTrait(const clang::EnumDecl *decl) override;
+
   void AddDefaultTrait(const clang::RecordDecl *decl) override;
 
   void AddDefaultTraitForUnion(const clang::RecordDecl *decl) override;
diff --git a/tests/multi-file/cross_tu_anon_enum_collision/out/refcount/cross_tu_anon_enum_collision.rs b/tests/multi-file/cross_tu_anon_enum_collision/out/refcount/cross_tu_anon_enum_collision.rs
index c7edae33..0ce84bdb 100644
--- a/tests/multi-file/cross_tu_anon_enum_collision/out/refcount/cross_tu_anon_enum_collision.rs
+++ b/tests/multi-file/cross_tu_anon_enum_collision/out/refcount/cross_tu_anon_enum_collision.rs
@@ -20,6 +20,14 @@ impl From<i32> for anon_0 {
     }
 }
 libcc2rs::impl_enum_inc_dec!(anon_0);
+impl ByteRepr for anon_0 {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <anon_0>::from(i32::from_bytes(buf))
+    }
+}
 pub fn a_value_1() -> i32 {
     let x: Value<i32> = Rc::new(RefCell::new(0));
     (*x.borrow_mut()) |= (anon_0::ALPHA as i32);
@@ -47,6 +55,14 @@ impl From<i32> for anon_3 {
     }
 }
 libcc2rs::impl_enum_inc_dec!(anon_3);
+impl ByteRepr for anon_3 {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <anon_3>::from(i32::from_bytes(buf))
+    }
+}
 pub fn b_value_2() -> i32 {
     let x: Value<i32> = Rc::new(RefCell::new(0));
     (*x.borrow_mut()) |= (anon_3::BETA as i32);
diff --git a/tests/multi-file/cross_tu_tag_collision/out/refcount/cross_tu_tag_collision.rs b/tests/multi-file/cross_tu_tag_collision/out/refcount/cross_tu_tag_collision.rs
index 5fd97a8f..90529368 100644
--- a/tests/multi-file/cross_tu_tag_collision/out/refcount/cross_tu_tag_collision.rs
+++ b/tests/multi-file/cross_tu_tag_collision/out/refcount/cross_tu_tag_collision.rs
@@ -51,6 +51,14 @@ impl From<i32> for widget_enum {
     }
 }
 libcc2rs::impl_enum_inc_dec!(widget_enum);
+impl ByteRepr for widget_enum {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <widget_enum>::from(i32::from_bytes(buf))
+    }
+}
 pub fn b_value_1() -> i32 {
     let w: Value<widget_enum> = Rc::new(RefCell::new(widget_enum::WIDGET_C));
     return ((*w.borrow()) as i32).clone();
diff --git a/tests/ub/out/refcount/enum_out_of_range_cast.rs b/tests/ub/out/refcount/enum_out_of_range_cast.rs
index 60538ac8..cdd50986 100644
--- a/tests/ub/out/refcount/enum_out_of_range_cast.rs
+++ b/tests/ub/out/refcount/enum_out_of_range_cast.rs
@@ -24,6 +24,14 @@ impl From<i32> for Color {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Color);
+impl ByteRepr for Color {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Color>::from(i32::from_bytes(buf))
+    }
+}
 pub fn main() {
     std::process::exit(main_0());
 }
diff --git a/tests/ub/out/refcount/enum_out_of_range_increment.rs b/tests/ub/out/refcount/enum_out_of_range_increment.rs
index 4809fa73..1b764f17 100644
--- a/tests/ub/out/refcount/enum_out_of_range_increment.rs
+++ b/tests/ub/out/refcount/enum_out_of_range_increment.rs
@@ -24,6 +24,14 @@ impl From<i32> for color {
     }
 }
 libcc2rs::impl_enum_inc_dec!(color);
+impl ByteRepr for color {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <color>::from(i32::from_bytes(buf))
+    }
+}
 pub fn main() {
     std::process::exit(main_0());
 }
diff --git a/tests/unit/out/refcount/anonymous_enum.rs b/tests/unit/out/refcount/anonymous_enum.rs
index 25de7201..9fbf91ed 100644
--- a/tests/unit/out/refcount/anonymous_enum.rs
+++ b/tests/unit/out/refcount/anonymous_enum.rs
@@ -22,6 +22,14 @@ impl From<i32> for anon_0 {
     }
 }
 libcc2rs::impl_enum_inc_dec!(anon_0);
+impl ByteRepr for anon_0 {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <anon_0>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Clone, Copy, PartialEq, Debug, Default)]
 enum anon_1 {
     #[default]
@@ -38,6 +46,14 @@ impl From<i32> for anon_1 {
     }
 }
 libcc2rs::impl_enum_inc_dec!(anon_1);
+impl ByteRepr for anon_1 {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <anon_1>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Default)]
 pub struct S {
     pub a: Value<i32>,
@@ -76,6 +92,14 @@ impl From<i32> for TdEnum {
     }
 }
 libcc2rs::impl_enum_inc_dec!(TdEnum);
+impl ByteRepr for TdEnum {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <TdEnum>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Clone, Copy, PartialEq, Debug, Default)]
 enum anon_2 {
     #[default]
@@ -92,6 +116,14 @@ impl From<i32> for anon_2 {
     }
 }
 libcc2rs::impl_enum_inc_dec!(anon_2);
+impl ByteRepr for anon_2 {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <anon_2>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Default)]
 pub struct WithAnonField {
     pub a: Value<i32>,
@@ -106,7 +138,18 @@ impl Clone for WithAnonField {
         this
     }
 }
-impl ByteRepr for WithAnonField {}
+impl ByteRepr for WithAnonField {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self.a.borrow()).to_bytes(&mut buf[0..4]);
+        (*self.field.borrow()).to_bytes(&mut buf[4..8]);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        Self {
+            a: Rc::new(RefCell::new(<i32>::from_bytes(&buf[0..4]))),
+            field: Rc::new(RefCell::new(<anon_2>::from_bytes(&buf[4..8]))),
+        }
+    }
+}
 pub fn main() {
     std::process::exit(main_0());
 }
@@ -127,6 +170,14 @@ fn main_0() -> i32 {
         }
     }
     libcc2rs::impl_enum_inc_dec!(anon_3);
+    impl ByteRepr for anon_3 {
+        fn to_bytes(&self, buf: &mut [u8]) {
+            (*self as i32).to_bytes(buf);
+        }
+        fn from_bytes(buf: &[u8]) -> Self {
+            <anon_3>::from(i32::from_bytes(buf))
+        }
+    };
     assert!(((anon_0::FIRST_A as i32) != (anon_0::FIRST_B as i32)));
     assert!(((anon_1::SECOND_A as i32) != (anon_1::SECOND_B as i32)));
     assert!(((anon_3::THIRD_A as i32) != (anon_3::THIRD_B as i32)));
diff --git a/tests/unit/out/refcount/anonymous_enum_c.rs b/tests/unit/out/refcount/anonymous_enum_c.rs
index 772ea6e5..199dc233 100644
--- a/tests/unit/out/refcount/anonymous_enum_c.rs
+++ b/tests/unit/out/refcount/anonymous_enum_c.rs
@@ -22,6 +22,14 @@ impl From<i32> for anon_0 {
     }
 }
 libcc2rs::impl_enum_inc_dec!(anon_0);
+impl ByteRepr for anon_0 {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <anon_0>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Clone, Copy, PartialEq, Debug, Default)]
 enum anon_1 {
     #[default]
@@ -38,6 +46,14 @@ impl From<i32> for anon_1 {
     }
 }
 libcc2rs::impl_enum_inc_dec!(anon_1);
+impl ByteRepr for anon_1 {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <anon_1>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Default)]
 pub struct S {
     pub a: Value<i32>,
@@ -68,6 +84,14 @@ impl From<i32> for TdEnum_enum {
     }
 }
 libcc2rs::impl_enum_inc_dec!(TdEnum_enum);
+impl ByteRepr for TdEnum_enum {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <TdEnum_enum>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Clone, Copy, PartialEq, Debug, Default)]
 enum anon_2 {
     #[default]
@@ -84,12 +108,31 @@ impl From<i32> for anon_2 {
     }
 }
 libcc2rs::impl_enum_inc_dec!(anon_2);
+impl ByteRepr for anon_2 {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <anon_2>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Default)]
 pub struct WithAnonField {
     pub a: Value<i32>,
     pub field: Value<anon_2>,
 }
-impl ByteRepr for WithAnonField {}
+impl ByteRepr for WithAnonField {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self.a.borrow()).to_bytes(&mut buf[0..4]);
+        (*self.field.borrow()).to_bytes(&mut buf[4..8]);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        Self {
+            a: Rc::new(RefCell::new(<i32>::from_bytes(&buf[0..4]))),
+            field: Rc::new(RefCell::new(<anon_2>::from_bytes(&buf[4..8]))),
+        }
+    }
+}
 pub fn main() {
     std::process::exit(main_0());
 }
@@ -110,6 +153,14 @@ fn main_0() -> i32 {
         }
     }
     libcc2rs::impl_enum_inc_dec!(anon_3);
+    impl ByteRepr for anon_3 {
+        fn to_bytes(&self, buf: &mut [u8]) {
+            (*self as i32).to_bytes(buf);
+        }
+        fn from_bytes(buf: &[u8]) -> Self {
+            <anon_3>::from(i32::from_bytes(buf))
+        }
+    };
     assert!(((((anon_0::FIRST_A as i32) != (anon_0::FIRST_B as i32)) as i32) != 0));
     assert!(((((anon_1::SECOND_A as i32) != (anon_1::SECOND_B as i32)) as i32) != 0));
     assert!(((((anon_3::THIRD_A as i32) != (anon_3::THIRD_B as i32)) as i32) != 0));
diff --git a/tests/unit/out/refcount/bool_condition_enum.rs b/tests/unit/out/refcount/bool_condition_enum.rs
index 1d7dc853..228c2f70 100644
--- a/tests/unit/out/refcount/bool_condition_enum.rs
+++ b/tests/unit/out/refcount/bool_condition_enum.rs
@@ -24,6 +24,14 @@ impl From<i32> for Code {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Code);
+impl ByteRepr for Code {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Code>::from(i32::from_bytes(buf))
+    }
+}
 pub fn main() {
     std::process::exit(main_0());
 }
diff --git a/tests/unit/out/refcount/bool_condition_enum_c.rs b/tests/unit/out/refcount/bool_condition_enum_c.rs
index f84c1a88..c22850e6 100644
--- a/tests/unit/out/refcount/bool_condition_enum_c.rs
+++ b/tests/unit/out/refcount/bool_condition_enum_c.rs
@@ -24,6 +24,14 @@ impl From<i32> for Code {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Code);
+impl ByteRepr for Code {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Code>::from(i32::from_bytes(buf))
+    }
+}
 pub fn main() {
     std::process::exit(main_0());
 }
diff --git a/tests/unit/out/refcount/bool_condition_logical.rs b/tests/unit/out/refcount/bool_condition_logical.rs
index 9b340849..815ea3f8 100644
--- a/tests/unit/out/refcount/bool_condition_logical.rs
+++ b/tests/unit/out/refcount/bool_condition_logical.rs
@@ -24,6 +24,14 @@ impl From<i32> for Code {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Code);
+impl ByteRepr for Code {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Code>::from(i32::from_bytes(buf))
+    }
+}
 thread_local!(
     pub static side_effect_0: Value<i32> = Rc::new(RefCell::new(0));
 );
diff --git a/tests/unit/out/refcount/bool_condition_logical_c.rs b/tests/unit/out/refcount/bool_condition_logical_c.rs
index a878ce93..e0bae274 100644
--- a/tests/unit/out/refcount/bool_condition_logical_c.rs
+++ b/tests/unit/out/refcount/bool_condition_logical_c.rs
@@ -24,6 +24,14 @@ impl From<i32> for Code {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Code);
+impl ByteRepr for Code {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Code>::from(i32::from_bytes(buf))
+    }
+}
 thread_local!(
     pub static side_effect_0: Value<i32> = Rc::new(RefCell::new(0));
 );
diff --git a/tests/unit/out/refcount/c_struct.rs b/tests/unit/out/refcount/c_struct.rs
index 0549baab..36ebdeb4 100644
--- a/tests/unit/out/refcount/c_struct.rs
+++ b/tests/unit/out/refcount/c_struct.rs
@@ -53,6 +53,14 @@ impl From<i32> for Color {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Color);
+impl ByteRepr for Color {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Color>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Default)]
 pub struct Inner {
     pub a: Value<i32>,
diff --git a/tests/unit/out/refcount/enum_default_in_static.rs b/tests/unit/out/refcount/enum_default_in_static.rs
index 96f3bd8e..0e6f4c29 100644
--- a/tests/unit/out/refcount/enum_default_in_static.rs
+++ b/tests/unit/out/refcount/enum_default_in_static.rs
@@ -24,12 +24,31 @@ impl From<i32> for Mode {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Mode);
+impl ByteRepr for Mode {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Mode>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Default)]
 pub struct Config {
     pub count: Value<i32>,
     pub mode: Value<Mode>,
 }
-impl ByteRepr for Config {}
+impl ByteRepr for Config {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self.count.borrow()).to_bytes(&mut buf[0..4]);
+        (*self.mode.borrow()).to_bytes(&mut buf[4..8]);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        Self {
+            count: Rc::new(RefCell::new(<i32>::from_bytes(&buf[0..4]))),
+            mode: Rc::new(RefCell::new(<Mode>::from_bytes(&buf[4..8]))),
+        }
+    }
+}
 thread_local!(
     pub static config_0: Value<Config> = <Value<Config>>::default();
 );
diff --git a/tests/unit/out/refcount/enum_increment.rs b/tests/unit/out/refcount/enum_increment.rs
index 25a24a2f..387ac2b6 100644
--- a/tests/unit/out/refcount/enum_increment.rs
+++ b/tests/unit/out/refcount/enum_increment.rs
@@ -26,6 +26,14 @@ impl From<i32> for color {
     }
 }
 libcc2rs::impl_enum_inc_dec!(color);
+impl ByteRepr for color {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <color>::from(i32::from_bytes(buf))
+    }
+}
 pub fn main() {
     std::process::exit(main_0());
 }
diff --git a/tests/unit/out/refcount/enum_int_interop.rs b/tests/unit/out/refcount/enum_int_interop.rs
index 887ea844..fea2807d 100644
--- a/tests/unit/out/refcount/enum_int_interop.rs
+++ b/tests/unit/out/refcount/enum_int_interop.rs
@@ -24,6 +24,14 @@ impl From<i32> for Color {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Color);
+impl ByteRepr for Color {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Color>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Clone, Copy, PartialEq, Debug, Default)]
 enum Option {
     #[default]
@@ -44,6 +52,14 @@ impl From<i32> for Option {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Option);
+impl ByteRepr for Option {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Option>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Clone, Copy, PartialEq, Debug, Default)]
 enum Tag {
     #[default]
@@ -62,6 +78,14 @@ impl From<i32> for Tag {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Tag);
+impl ByteRepr for Tag {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Tag>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Default)]
 pub struct Entry {
     pub name: Value<Ptr<u8>>,
diff --git a/tests/unit/out/refcount/enum_int_interop_c.rs b/tests/unit/out/refcount/enum_int_interop_c.rs
index 793b0c4e..728693c1 100644
--- a/tests/unit/out/refcount/enum_int_interop_c.rs
+++ b/tests/unit/out/refcount/enum_int_interop_c.rs
@@ -24,6 +24,14 @@ impl From<i32> for Color {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Color);
+impl ByteRepr for Color {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Color>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Clone, Copy, PartialEq, Debug, Default)]
 enum Option {
     #[default]
@@ -44,6 +52,14 @@ impl From<i32> for Option {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Option);
+impl ByteRepr for Option {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Option>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Clone, Copy, PartialEq, Debug, Default)]
 enum Tag_enum {
     #[default]
@@ -62,6 +78,14 @@ impl From<i32> for Tag_enum {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Tag_enum);
+impl ByteRepr for Tag_enum {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Tag_enum>::from(i32::from_bytes(buf))
+    }
+}
 #[derive(Default)]
 pub struct Entry {
     pub name: Value<Ptr<u8>>,
diff --git a/tests/unit/out/refcount/switch_char.rs b/tests/unit/out/refcount/switch_char.rs
index d6513ca2..099f04ef 100644
--- a/tests/unit/out/refcount/switch_char.rs
+++ b/tests/unit/out/refcount/switch_char.rs
@@ -48,6 +48,14 @@ impl From<i32> for Color {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Color);
+impl ByteRepr for Color {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Color>::from(i32::from_bytes(buf))
+    }
+}
 pub fn main() {
     std::process::exit(main_0());
 }
diff --git a/tests/unit/out/refcount/switch_enum.rs b/tests/unit/out/refcount/switch_enum.rs
index 0c2c264a..f6e9a11e 100644
--- a/tests/unit/out/refcount/switch_enum.rs
+++ b/tests/unit/out/refcount/switch_enum.rs
@@ -24,6 +24,14 @@ impl From<i32> for Color {
     }
 }
 libcc2rs::impl_enum_inc_dec!(Color);
+impl ByteRepr for Color {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <Color>::from(i32::from_bytes(buf))
+    }
+}
 pub fn switch_enum_0(c: Color) -> i32 {
     let c: Value<Color> = Rc::new(RefCell::new(c));
     'switch: {
diff --git a/tests/unit/out/refcount/va_arg_non_primitive_ptrs.rs b/tests/unit/out/refcount/va_arg_non_primitive_ptrs.rs
index a6d331bb..acc2fc1d 100644
--- a/tests/unit/out/refcount/va_arg_non_primitive_ptrs.rs
+++ b/tests/unit/out/refcount/va_arg_non_primitive_ptrs.rs
@@ -32,6 +32,14 @@ impl From<i32> for opt {
     }
 }
 libcc2rs::impl_enum_inc_dec!(opt);
+impl ByteRepr for opt {
+    fn to_bytes(&self, buf: &mut [u8]) {
+        (*self as i32).to_bytes(buf);
+    }
+    fn from_bytes(buf: &[u8]) -> Self {
+        <opt>::from(i32::from_bytes(buf))
+    }
+}
 pub fn dispatch_0(option: i32, __args: &[VaArg]) -> i32 {
     let option: Value<i32> = Rc::new(RefCell::new(option));
     let ap: Value<VaList> = Rc::new(RefCell::new(VaList::default()));