From b6ea6f91922fbc04976e58b74db8f81244f37465 Mon Sep 17 00:00:00 2001
From: Alyssa Haroldsen <kupiakos@google.com>
Date: Wed, 17 Jan 2024 16:50:36 -0800
Subject: [PATCH] Remove Deref from RepeatedMut

PiperOrigin-RevId: 599328590
---
 rust/repeated.rs                            | 51 +++++++++++++--------
 rust/test/shared/accessors_repeated_test.rs | 11 +++--
 2 files changed, 38 insertions(+), 24 deletions(-)

diff --git a/rust/repeated.rs b/rust/repeated.rs
index 498b55077a..8dc67f4348 100644
--- a/rust/repeated.rs
+++ b/rust/repeated.rs
@@ -53,19 +53,9 @@ pub struct RepeatedMut<'msg, T: ?Sized> {
 
 unsafe impl<'msg, T: ?Sized> Sync for RepeatedMut<'msg, T> {}
 
-impl<'msg, T: ?Sized> Deref for RepeatedMut<'msg, T> {
-    type Target = RepeatedView<'msg, T>;
-    fn deref(&self) -> &Self::Target {
-        // SAFETY:
-        //   - `RepeatedView<'msg, T>` is `#[repr(transparent)]` over
-        //     `RawRepeatedField`.
-        unsafe { &*(&self.inner.raw as *const RawRepeatedField as *const RepeatedView<'msg, T>) }
-    }
-}
-
 impl<'msg, T: ?Sized> Debug for RepeatedMut<'msg, T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("RepeatedMut").field("raw", &self.raw).finish()
+        f.debug_struct("RepeatedMut").field("raw", &self.inner.raw).finish()
     }
 }
 
@@ -146,6 +136,32 @@ where
         self.inner.raw
     }
 
+    /// Gets the length of the repeated field.
+    pub fn len(&self) -> usize {
+        self.as_view().len()
+    }
+
+    /// Returns true if the repeated field has no values.
+    pub fn is_empty(&self) -> bool {
+        self.len() == 0
+    }
+
+    /// Gets the value at `index`.
+    ///
+    /// Returns `None` if `index > len`.
+    pub fn get(&self, index: usize) -> Option<View<T>> {
+        self.as_view().get(index)
+    }
+
+    /// Gets the value at `index` without bounds-checking.
+    ///
+    /// # Safety
+    /// Undefined behavior if `index >= len`
+    pub unsafe fn get_unchecked(&self, index: usize) -> View<T> {
+        // SAFETY: in-bounds as promised
+        unsafe { self.as_view().get_unchecked(index) }
+    }
+
     /// Appends `val` to the end of the repeated field.
     pub fn push(&mut self, val: View<T>) {
         T::repeated_push(self.as_mut(), val);
@@ -173,12 +189,9 @@ where
         unsafe { T::repeated_set_unchecked(self.as_mut(), index, val) }
     }
 
-    /// Returns the value at `index`.
-    // This is defined as an inherent function to prevent `MutProxy::get` from being
-    // preferred over `RepeatedView::get`. The former gets priority as it does
-    // not require a deref.
-    pub fn get(&self, index: usize) -> Option<View<T>> {
-        self.as_view().get(index)
+    /// Iterates over the values in the repeated field.
+    pub fn iter(&self) -> RepeatedIter<T> {
+        self.as_view().into_iter()
     }
 
     /// Copies from the `src` repeated field into this one.
@@ -343,14 +356,14 @@ where
     type Proxied = Repeated<T>;
 
     fn as_view(&self) -> View<'_, Self::Proxied> {
-        **self
+        RepeatedView { raw: self.inner.raw, _phantom: PhantomData }
     }
 
     fn into_view<'shorter>(self) -> View<'shorter, Self::Proxied>
     where
         'msg: 'shorter,
     {
-        *self.into_mut::<'shorter>()
+        RepeatedView { raw: self.inner.raw, _phantom: PhantomData }
     }
 }
 
diff --git a/rust/test/shared/accessors_repeated_test.rs b/rust/test/shared/accessors_repeated_test.rs
index 0f9d724505..1852847b4f 100644
--- a/rust/test/shared/accessors_repeated_test.rs
+++ b/rust/test/shared/accessors_repeated_test.rs
@@ -7,6 +7,7 @@
 
 use googletest::prelude::*;
 use paste::paste;
+use protobuf::ViewProxy;
 use unittest_proto::proto2_unittest::{TestAllTypes, TestAllTypes_, TestAllTypes_::NestedMessage};
 
 macro_rules! generate_repeated_numeric_test {
@@ -38,7 +39,7 @@ macro_rules! generate_repeated_numeric_test {
                   elements_are![eq(2 as $t), eq(1 as $t), eq(0 as $t)]
               );
               assert_that!(
-                  (*mutator).into_iter().collect::<Vec<_>>(),
+                  mutator.as_view().into_iter().collect::<Vec<_>>(),
                   elements_are![eq(2 as $t), eq(1 as $t), eq(0 as $t)]
               );
 
@@ -60,7 +61,7 @@ macro_rules! generate_repeated_numeric_test {
               for i in 0..5 {
                   mutator2.push(i as $t);
               }
-              protobuf::MutProxy::set(&mut mutator, *mutator2);
+              protobuf::MutProxy::set(&mut mutator, mutator2.as_view());
 
               assert_that!(
                   mutator.iter().collect::<Vec<_>>(),
@@ -103,7 +104,7 @@ fn test_repeated_bool_accessors() {
 
     assert_that!(mutator.iter().collect::<Vec<_>>(), elements_are![eq(false), eq(true), eq(false)]);
     assert_that!(
-        (*mutator).into_iter().collect::<Vec<_>>(),
+        mutator.as_view().into_iter().collect::<Vec<_>>(),
         elements_are![eq(false), eq(true), eq(false)]
     );
 
@@ -141,7 +142,7 @@ fn test_repeated_enum_accessors() {
         elements_are![eq(NestedEnum::Bar), eq(NestedEnum::Baz), eq(NestedEnum::Foo)]
     );
     assert_that!(
-        (*mutator).into_iter().collect::<Vec<_>>(),
+        mutator.as_view().into_iter().collect::<Vec<_>>(),
         elements_are![eq(NestedEnum::Bar), eq(NestedEnum::Baz), eq(NestedEnum::Foo)]
     );
 
@@ -160,7 +161,7 @@ fn test_repeated_bool_set() {
     for _ in 0..5 {
         mutator2.push(true);
     }
-    protobuf::MutProxy::set(&mut mutator, *mutator2);
+    protobuf::MutProxy::set(&mut mutator, mutator2.as_view());
 
     assert_that!(mutator.iter().collect::<Vec<_>>(), eq(mutator2.iter().collect::<Vec<_>>()));
 }