rust: pin-init: cleanup workaround for old Rust compiler

The workaround mentions it's for Rust versions before 1.81. The minimum is
now 1.82, thus clean up.

Link: https://patch.msgid.link/20260428-pin-init-sync-v1-9-07f9bd3859fb@garyguo.net
Signed-off-by: Gary Guo <gary@garyguo.net>

2 files changed, 3 insertions, 24 deletions

diff --git a/rust/pin-init/internal/src/init.rs b/rust/pin-init/internal/src/init.rs
index 487ee0013faf..b0bfe44695e1 100644
--- a/rust/pin-init/internal/src/init.rs
+++ b/rust/pin-init/internal/src/init.rs
@@ -172,14 +172,7 @@ pub(crate) fn expand(
             init(slot).map(|__InitOk| ())
         };
         // SAFETY: TODO
-        let init = unsafe { ::pin_init::#init_from_closure::<_, #error>(init) };
-        // FIXME: this let binding is required to avoid a compiler error (cycle when computing the
-        // opaque type returned by this function) before Rust 1.81. Remove after MSRV bump.
-        #[allow(
-            clippy::let_and_return,
-            reason = "some clippy versions warn about the let binding"
-        )]
-        init
+        unsafe { ::pin_init::#init_from_closure::<_, #error>(init) }
     }})
 }
 
diff --git a/rust/pin-init/src/lib.rs b/rust/pin-init/src/lib.rs
index 9b76cf5597c6..80c476e605f7 100644
--- a/rust/pin-init/src/lib.rs
+++ b/rust/pin-init/src/lib.rs
@@ -1139,14 +1139,7 @@ pub const unsafe fn init_from_closure<T: ?Sized, E>(
 pub const unsafe fn cast_pin_init<T, U, E>(init: impl PinInit<T, E>) -> impl PinInit<U, E> {
     // SAFETY: initialization delegated to a valid initializer. Cast is valid by function safety
     // requirements.
-    let res = unsafe { pin_init_from_closure(|ptr: *mut U| init.__pinned_init(ptr.cast::<T>())) };
-    // FIXME: this let binding is required to avoid a compiler error (cycle when computing the opaque
-    // type returned by this function) before Rust 1.81. Remove after MSRV bump.
-    #[allow(
-        clippy::let_and_return,
-        reason = "some clippy versions warn about the let binding"
-    )]
-    res
+    unsafe { pin_init_from_closure(|ptr: *mut U| init.__pinned_init(ptr.cast::<T>())) }
 }
 
 /// Changes the to be initialized type.
@@ -1158,14 +1151,7 @@ pub const unsafe fn cast_pin_init<T, U, E>(init: impl PinInit<T, E>) -> impl Pin
 pub const unsafe fn cast_init<T, U, E>(init: impl Init<T, E>) -> impl Init<U, E> {
     // SAFETY: initialization delegated to a valid initializer. Cast is valid by function safety
     // requirements.
-    let res = unsafe { init_from_closure(|ptr: *mut U| init.__init(ptr.cast::<T>())) };
-    // FIXME: this let binding is required to avoid a compiler error (cycle when computing the opaque
-    // type returned by this function) before Rust 1.81. Remove after MSRV bump.
-    #[allow(
-        clippy::let_and_return,
-        reason = "some clippy versions warn about the let binding"
-    )]
-    res
+    unsafe { init_from_closure(|ptr: *mut U| init.__init(ptr.cast::<T>())) }
 }
 
 /// An initializer that leaves the memory uninitialized.