Remove the Proxy trait

This trait does not seem to serve any useful purpose beyond what's already
covered by the `ViewProxy` and `MutProxy` traits, so let's remove it to
simplify things.

PiperOrigin-RevId: 814844765

Author: acozzette

rust/cord.rs

@@ -7,8 +7,7 @@
 
 use crate::__internal::{Private, SealedInternal};
 use crate::{
-    AsView, IntoProxied, IntoView, ProtoBytes, ProtoStr, ProtoString, Proxied, Proxy, View,
-    ViewProxy,
+    AsView, IntoProxied, IntoView, ProtoBytes, ProtoStr, ProtoString, Proxied, View, ViewProxy,
 };
 use paste::paste;
 use std::cmp::PartialEq;
@@ -41,8 +40,6 @@ macro_rules! impl_cord_types {
             }
           }
 
-          impl<'msg> Proxy<'msg> for [< $t Cow>]<'msg> {}
-
           impl<'msg> ViewProxy<'msg> for [< $t Cow>]<'msg> {}
 
           impl<'msg> AsView for [< $t Cow>]<'msg> {

rust/map.rs

@@ -7,7 +7,7 @@
 
 use crate::{
     AsMut, AsView, IntoMut, IntoProxied, IntoView, Message, Mut, MutProxied, MutProxy, Proxied,
-    Proxy, View, ViewProxy,
+    View, ViewProxy,
     __internal::runtime::{InnerMap, InnerMapMut, RawMap, RawMapIter},
     __internal::{Private, SealedInternal},
 };
@@ -141,8 +141,6 @@ impl<K: Proxied, V: ProxiedInMapValue<K>> AsMut for Map<K, V> {
 
 impl<'msg, K: Proxied, V: ProxiedInMapValue<K>> SealedInternal for MapView<'msg, K, V> {}
 
-impl<'msg, K: Proxied, V: ProxiedInMapValue<K>> Proxy<'msg> for MapView<'msg, K, V> {}
-
 impl<'msg, K: Proxied, V: ProxiedInMapValue<K>> AsView for MapView<'msg, K, V> {
     type Proxied = Map<K, V>;
 
@@ -164,8 +162,6 @@ impl<'msg, K: Proxied, V: ProxiedInMapValue<K>> ViewProxy<'msg> for MapView<'msg
 
 impl<'msg, K: Proxied, V: ProxiedInMapValue<K>> SealedInternal for MapMut<'msg, K, V> {}
 
-impl<'msg, K: Proxied, V: ProxiedInMapValue<K>> Proxy<'msg> for MapMut<'msg, K, V> {}
-
 impl<'msg, K: Proxied, V: ProxiedInMapValue<K>> AsView for MapMut<'msg, K, V> {
     type Proxied = Map<K, V>;
 

rust/primitive.rs

@@ -5,7 +5,7 @@
 // license that can be found in the LICENSE file or at
 // https://developers.google.com/open-source/licenses/bsd
 use crate::__internal::SealedInternal;
-use crate::{AsView, IntoView, Proxied, Proxy, ViewProxy};
+use crate::{AsView, IntoView, Proxied, ViewProxy};
 
 macro_rules! impl_singular_primitives {
   ($($t:ty),*) => {
@@ -16,9 +16,6 @@ macro_rules! impl_singular_primitives {
             type View<'msg> = $t;
         }
 
-        impl<'msg> Proxy<'msg> for $t {
-        }
-
         impl AsView for $t {
             type Proxied = $t;
 

rust/proxied.rs

@@ -45,7 +45,6 @@
 //! indirection between the user and the internal memory representation.
 
 use crate::__internal::{Private, SealedInternal};
-use std::fmt::Debug;
 
 /// A type that can be accessed through a reference-like proxy.
 ///
@@ -201,24 +200,14 @@ pub trait IntoMut<'msg>: SealedInternal + AsMut {
         'msg: 'shorter;
 }
 
-/// Declares conversion operations common to all proxies (both views and mut
-/// proxies).
-///
-/// This trait is intentionally made non-object-safe to prevent a potential
-/// future incompatible change.
-pub trait Proxy<'msg>:
-    SealedInternal + 'msg + IntoView<'msg> + Sync + Unpin + Sized + Debug
-{
-}
-
 /// Declares conversion operations common to view proxies.
-pub trait ViewProxy<'msg>: SealedInternal + Proxy<'msg> + Send {}
+pub trait ViewProxy<'msg>: SealedInternal + Send + IntoView<'msg> {}
 
 /// Declares operations common to all mut proxies.
 ///
 /// This trait is intentionally made non-object-safe to prevent a potential
 /// future incompatible change.
-pub trait MutProxy<'msg>: SealedInternal + Proxy<'msg> + AsMut + IntoMut<'msg> {
+pub trait MutProxy<'msg>: SealedInternal + AsMut + IntoMut<'msg> + IntoView<'msg> {
     /// Gets an immutable view of this field. This is shorthand for `as_view`.
     ///
     /// This provides a shorter lifetime than `into_view` but can also be called
@@ -306,8 +295,6 @@ mod tests {
         }
     }
 
-    impl<'msg> Proxy<'msg> for MyProxiedView<'msg> {}
-
     impl<'msg> ViewProxy<'msg> for MyProxiedView<'msg> {}
 
     impl<'msg> AsView for MyProxiedView<'msg> {
@@ -334,8 +321,6 @@ mod tests {
 
     impl<'msg> SealedInternal for MyProxiedMut<'msg> {}
 
-    impl<'msg> Proxy<'msg> for MyProxiedMut<'msg> {}
-
     impl<'msg> AsView for MyProxiedMut<'msg> {
         type Proxied = MyProxied;
 

rust/repeated.rs

@@ -16,7 +16,7 @@ use std::marker::PhantomData;
 
 use crate::{
     AsMut, AsView, IntoMut, IntoProxied, IntoView, Message, Mut, MutProxied, MutProxy, Proxied,
-    Proxy, View, ViewProxy,
+    View, ViewProxy,
     __internal::runtime::{InnerRepeated, InnerRepeatedMut, RawRepeatedField},
     __internal::{Private, SealedInternal},
 };
@@ -460,8 +460,6 @@ where
 
 impl<'msg, T> SealedInternal for RepeatedView<'msg, T> where T: ProxiedInRepeated + 'msg {}
 
-impl<'msg, T> Proxy<'msg> for RepeatedView<'msg, T> where T: ProxiedInRepeated + 'msg {}
-
 impl<'msg, T> AsView for RepeatedView<'msg, T>
 where
     T: ProxiedInRepeated + 'msg,
@@ -491,8 +489,6 @@ impl<'msg, T> ViewProxy<'msg> for RepeatedView<'msg, T> where T: ProxiedInRepeat
 
 impl<'msg, T> SealedInternal for RepeatedMut<'msg, T> where T: ProxiedInRepeated + 'msg {}
 
-impl<'msg, T> Proxy<'msg> for RepeatedMut<'msg, T> where T: ProxiedInRepeated + 'msg {}
-
 impl<'msg, T> AsView for RepeatedMut<'msg, T>
 where
     T: ProxiedInRepeated + 'msg,

rust/shared.rs

@@ -25,7 +25,7 @@ pub use crate::cord::{ProtoBytesCow, ProtoStringCow};
 pub use crate::map::{Map, MapIter, MapMut, MapView, ProxiedInMapValue};
 pub use crate::optional::Optional;
 pub use crate::proxied::{
-    AsMut, AsView, IntoMut, IntoProxied, IntoView, Mut, MutProxied, MutProxy, Proxied, Proxy, View,
+    AsMut, AsView, IntoMut, IntoProxied, IntoView, Mut, MutProxied, MutProxy, Proxied, View,
     ViewProxy,
 };
 pub use crate::r#enum::{Enum, UnknownEnumValue};

rust/string.rs

@@ -13,7 +13,7 @@ use crate::__internal::runtime::InnerProtoString;
 use crate::__internal::{Private, SealedInternal};
 use crate::{
     utf8::Utf8Chunks, AsView, IntoProxied, IntoView, Mut, MutProxied, MutProxy, Optional, Proxied,
-    Proxy, View, ViewProxy,
+    View, ViewProxy,
 };
 use std::borrow::Cow;
 use std::cmp::{Eq, Ord, Ordering, PartialEq, PartialOrd};
@@ -131,8 +131,6 @@ impl IntoProxied<ProtoBytes> for Arc<[u8]> {
 
 impl SealedInternal for &[u8] {}
 
-impl<'msg> Proxy<'msg> for &'msg [u8] {}
-
 impl AsView for &[u8] {
     type Proxied = ProtoBytes;
 
@@ -534,8 +532,6 @@ impl AsView for ProtoString {
     }
 }
 
-impl<'msg> Proxy<'msg> for &'msg ProtoStr {}
-
 impl AsView for &ProtoStr {
     type Proxied = ProtoString;
 

src/google/protobuf/compiler/rust/enum.cc

@@ -277,7 +277,6 @@ void GenerateEnumDefinition(Context& ctx, const EnumDescriptor& desc,
         type View<'a> = $name$;
       }
 
-      impl $pb$::Proxy<'_> for $name$ {}
       impl $pb$::ViewProxy<'_> for $name$ {}
 
       impl $pb$::AsView for $name$ {

src/google/protobuf/compiler/rust/message.cc

@@ -608,7 +608,6 @@ void GenerateRs(Context& ctx, const Descriptor& msg, const upb::DefPool& pool) {
         // - `$Msg$View` does not use thread-local data.
         unsafe impl Send for $Msg$View<'_> {}
 
-        impl<'msg> $pb$::Proxy<'msg> for $Msg$View<'msg> {}
         impl<'msg> $pb$::ViewProxy<'msg> for $Msg$View<'msg> {}
 
         impl<'msg> $pb$::AsView for $Msg$View<'msg> {
@@ -683,7 +682,6 @@ void GenerateRs(Context& ctx, const Descriptor& msg, const upb::DefPool& pool) {
         // - `$Msg$Mut` does not perform any shared mutation.
         unsafe impl Sync for $Msg$Mut<'_> {}
 
-        impl<'msg> $pb$::Proxy<'msg> for $Msg$Mut<'msg> {}
         impl<'msg> $pb$::MutProxy<'msg> for $Msg$Mut<'msg> {}
 
         impl<'msg> $pb$::AsView for $Msg$Mut<'msg> {