Add .to_owned(&self)->Msg functions to MsgMut and MsgView

PiperOrigin-RevId: 631686314

rust/test/shared/accessors_test.rs

@@ -8,7 +8,7 @@
 //! Tests covering accessors for singular bool, int32, int64, and bytes fields.
 
 use googletest::prelude::*;
-use protobuf::{MutProxy, Optional};
+use protobuf::Optional;
 use unittest_proto::{test_all_types, TestAllTypes};
 
 #[test]
@@ -498,15 +498,13 @@ fn test_nonempty_default_string_accessors() {
 
 #[test]
 fn test_singular_msg_field() {
-    use test_all_types::*;
-
     let mut msg = TestAllTypes::new();
     let msg_view = msg.optional_nested_message();
     // testing reading an int inside a view
     assert_that!(msg_view.bb(), eq(0));
 
     assert_that!(msg.has_optional_nested_message(), eq(false));
-    let mut nested_msg_mut = msg.optional_nested_message_mut();
+    let nested_msg_mut = msg.optional_nested_message_mut();
     // test reading an int inside a mut
     assert_that!(nested_msg_mut.bb(), eq(0));
 
@@ -780,3 +778,27 @@ fn test_submsg_setter() {
 
     assert_that!(parent.optional_nested_message().bb(), eq(7));
 }
+
+#[test]
+fn test_to_owned() {
+    let mut m = TestAllTypes::new();
+    m.set_optional_int32(42);
+    let clone = m.as_view().to_owned();
+    assert_that!(clone.optional_int32(), eq(42));
+
+    // to_owned should create a new message (modifying the original shouldn't affect
+    // the to_owned).
+    m.clear_optional_int32();
+    assert_that!(m.has_optional_int32(), eq(false));
+    assert_that!(clone.has_optional_int32(), eq(true));
+    assert_that!(clone.optional_int32(), eq(42));
+
+    let mut submsg_mut = m.optional_nested_message_mut();
+    submsg_mut.set_bb(7);
+    let submsg_clone = submsg_mut.to_owned();
+    assert_that!(submsg_clone.bb(), eq(7));
+    assert_that!(submsg_mut.bb(), eq(7));
+    submsg_mut.set_bb(8);
+    assert_that!(submsg_clone.bb(), eq(7));
+    assert_that!(submsg_mut.bb(), eq(8));
+}

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

@@ -911,6 +911,10 @@ void GenerateRs(Context& ctx, const Descriptor& msg) {
             $Msg::serialize$
           }
 
+          pub fn to_owned(&self) -> $Msg$ {
+            $pb$::IntoProxied::into(*self, $pbi$::Private)
+          }
+
           $accessor_fns_for_views$
         }
 
@@ -986,6 +990,10 @@ void GenerateRs(Context& ctx, const Descriptor& msg) {
             $pb$::ViewProxy::as_view(self).serialize()
           }
 
+          pub fn to_owned(&self) -> $Msg$ {
+            $pb$::ViewProxy::as_view(self).to_owned()
+          }
+
           $get_upb_minitable$
 
           $raw_arena_getter_for_msgmut$