commit ab11a0d1a82551755f76a72158f47b0a50bab755
author Jakob Buchgraber <buchgr@google.com> Mon Nov 27 08:14:21 2023 -0800
committer Copybara-Service <copybara-worker@google.com> Mon Nov 27 08:18:41 2023 -0800
tree bd93891b631b16e1a2c0626f19e2972fb17a6c14
parent f9929e997ec7862ec371462d2c09e764f19d16ca

Name the lifetime in the signature of SettableValue.set_on()

This change names the lifetime of Mut<'a, T> and requires that T outlives 'a. The motivation for this change came up while implementing `Map<K, ProtoStr>`. The Map implementation makes it so that `V` needs to implement the `MapWithKeyOps` trait which has an associated type with a lifetime (`Value<'a>`. The lifetime bound on `T` ensures that e.g. for `MapWithKeyOps<Value<'b>=&'b ProtoStr>` `'a` outlives `'b`.

PiperOrigin-RevId: 585657154

rust/optional.rs

diff --git a/rust/optional.rs b/rust/optional.rs
index 3c49d7f..ba9955b 100644
--- a/rust/optional.rs
+++ b/rust/optional.rs
@@ -589,7 +589,10 @@
     }
 
     impl SettableValue<VtableProxied> for View<'_, VtableProxied> {
-        fn set_on(self, _private: Private, mutator: Mut<VtableProxied>) {
+        fn set_on<'a>(self, _private: Private, mutator: Mut<'a, VtableProxied>)
+        where
+            VtableProxied: 'a,
+        {
             SettableValue::<VtableProxied>::set_on(self.val(), Private, mutator)
         }
 
@@ -603,7 +606,10 @@
     }
 
     impl SettableValue<VtableProxied> for i32 {
-        fn set_on(self, _private: Private, mutator: Mut<VtableProxied>) {
+        fn set_on<'a>(self, _private: Private, mutator: Mut<'a, VtableProxied>)
+        where
+            VtableProxied: 'a,
+        {
             (mutator.vtable.set)(mutator.msg, self)
         }