cmov: additional clippy lints

Enables the following and fixes violations if any:
- `clippy::ref_as_ptr`
- `clippy::return_self_not_must_use`
- `clippy::semicolon_if_nothing_returned`

Author: tarcieri

cmov/src/lib.rs

@@ -15,6 +15,9 @@
     clippy::mod_module_files,
     clippy::panic,
     clippy::panic_in_result_fn,
+    clippy::ref_as_ptr,
+    clippy::return_self_not_must_use,
+    clippy::semicolon_if_nothing_returned,
     clippy::std_instead_of_alloc,
     clippy::std_instead_of_core,
     clippy::unwrap_used,
@@ -50,7 +53,7 @@ pub trait Cmov {
     /// Moves `value` to `self` in constant-time if `condition` is equal to zero.
     fn cmovz(&mut self, value: &Self, condition: Condition) {
         let nz = masknz!(condition: Condition);
-        self.cmovnz(value, !nz)
+        self.cmovnz(value, !nz);
     }
 }
 

cmov/src/slice.rs

@@ -3,7 +3,7 @@
 use crate::{Cmov, CmovEq, Condition};
 use core::{
     ops::{BitOrAssign, Shl},
-    slice,
+    ptr, slice,
 };
 
 // Uses 64-bit words on 64-bit targets, 32-bit everywhere else
@@ -267,9 +267,9 @@ unsafe fn cast_slice<T, U>(slice: &[T]) -> &[U] {
     // SAFETY:
     // - Slices are of same-sized/aligned types as asserted above.
     // - It's up to the caller to ensure the pointer cast from `T` to `U` itself is valid.
-    #[allow(trivial_casts, unsafe_code)]
+    #[allow(unsafe_code)]
     unsafe {
-        &*((slice as *const [T]) as *const [U])
+        &*(ptr::from_ref::<[T]>(slice) as *const [U])
     }
 }
 
@@ -287,9 +287,9 @@ unsafe fn cast_slice_mut<T, U>(slice: &mut [T]) -> &mut [U] {
     // SAFETY:
     // - Slices are of same-sized/aligned types as asserted above.
     // - It's up to the caller to ensure the pointer cast from `T` to `U` itself is valid.
-    #[allow(trivial_casts, unsafe_code)]
+    #[allow(unsafe_code)]
     unsafe {
-        &mut *((slice as *mut [T]) as *mut [U])
+        &mut *(ptr::from_mut::<[T]>(slice) as *mut [U])
     }
 }