rust: pin-init: internal: remove associated type of `HasInitData`

There is only a single implementation, the associated type is not
necessary. Remove it, and rename `AllData` to `InitData` to be a more
meaningful name.

The single implementation also means that "unsafe" is redundant, so remove
it as well.

Link: https://patch.msgid.link/20260923-dev-pin-data-diag-v1-2-e4d7193569e5@garyguo.net
Signed-off-by: Gary Guo <gary@garyguo.net>

1 files changed, 14 insertions, 23 deletions

diff --git a/rust/pin-init/src/__internal.rs b/rust/pin-init/src/__internal.rs
index 532ddcdc1c6a..e5f75432fe87 100644
--- a/rust/pin-init/src/__internal.rs
+++ b/rust/pin-init/src/__internal.rs
@@ -73,30 +73,31 @@ pub unsafe trait HasPinData {
     fn __pin_data() -> Self::PinData;
 }
 
-/// This trait is automatically implemented for every type. It aims to provide the same type
-/// inference help as `HasPinData`.
+/// This trait is automatically implemented for every type.
 ///
-/// # Safety
-///
-/// Only the `init` module is allowed to use this trait.
-pub unsafe trait HasInitData {
-    type InitData;
-
-    fn __init_data() -> Self::InitData;
+/// It aims to provide type inference help; `PATH::__init_data()` would be able to retrieve an
+/// instance of `InitData<PATH<Generics>>` without having to mention the generics explicitly.
+pub trait HasInitData {
+    #[inline]
+    fn __init_data() -> InitData<Self> {
+        InitData(PhantomInvariant::new())
+    }
 }
 
-pub struct AllData<T: ?Sized>(PhantomInvariant<T>);
+impl<T: ?Sized> HasInitData for T {}
+
+pub struct InitData<T: ?Sized>(PhantomInvariant<T>);
 
-impl<T: ?Sized> Clone for AllData<T> {
+impl<T: ?Sized> Clone for InitData<T> {
     #[inline]
     fn clone(&self) -> Self {
         *self
     }
 }
 
-impl<T: ?Sized> Copy for AllData<T> {}
+impl<T: ?Sized> Copy for InitData<T> {}
 
-impl<T: ?Sized> AllData<T> {
+impl<T: ?Sized> InitData<T> {
     /// Type inference helper function.
     #[inline(always)]
     pub fn __make_closure<F, E>(self, f: F) -> F
@@ -107,16 +108,6 @@ impl<T: ?Sized> AllData<T> {
     }
 }
 
-// SAFETY: TODO.
-unsafe impl<T: ?Sized> HasInitData for T {
-    type InitData = AllData<T>;
-
-    #[inline]
-    fn __init_data() -> Self::InitData {
-        AllData(PhantomInvariant::new())
-    }
-}
-
 /// Stack initializer helper type. Use [`stack_pin_init`] instead of this primitive.
 ///
 /// # Invariants