[PATCH] rust: types: Make Opaque::get const

[Boqun Feng <boqun.feng@gmail.com>]

To support a potential usage:

    static foo: Opaque<Foo> = ..; // Or defined in an extern block.

    ...

    fn bar() {
        let ptr = foo.get();
    }

`Opaque::get` need to be `const`, otherwise compiler will complain
because calls on statics are limited to const functions.

Also `Opaque::get` should be naturally `const` since it's a composition
of two `const` functions: `UnsafeCell::get` and `ptr::cast`.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
---
 rust/kernel/types.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs
index 0949f9971074..25953c8f8acf 100644
--- a/rust/kernel/types.rs
+++ b/rust/kernel/types.rs
@@ -315,7 +315,7 @@ pub fn ffi_init(init_func: impl FnOnce(*mut T)) -> impl PinInit<Self> {
     }
 
     /// Returns a raw pointer to the opaque data.
-    pub fn get(&self) -> *mut T {
+    pub const fn get(&self) -> *mut T {
         UnsafeCell::get(&self.value).cast::<T>()
     }
 
-- 
2.44.0