| use core::mem; |
| use core::ptr::{self, NonNull}; |
| use core::slice; |
| |
| #[repr(C)] |
| pub struct RustSlice { |
| pub(crate) repr: NonNull<[()]>, |
| } |
| |
| impl RustSlice { |
| pub fn from_ref<T>(slice: &[T]) -> Self { |
| let ptr = ptr::slice_from_raw_parts::<()>(slice.as_ptr().cast(), slice.len()); |
| RustSlice { |
| repr: unsafe { NonNull::new_unchecked(ptr as *mut _) }, |
| } |
| } |
| |
| pub fn from_mut<T>(slice: &mut [T]) -> Self { |
| let ptr = ptr::slice_from_raw_parts_mut(slice.as_mut_ptr().cast(), slice.len()); |
| RustSlice { |
| repr: unsafe { NonNull::new_unchecked(ptr) }, |
| } |
| } |
| |
| pub unsafe fn as_slice<'a, T>(self) -> &'a [T] { |
| let ptr = self.repr.as_ptr(); |
| let len = self.repr.as_ref().len(); |
| slice::from_raw_parts(ptr.cast(), len) |
| } |
| |
| pub unsafe fn as_mut_slice<'a, T>(self) -> &'a mut [T] { |
| let ptr = self.repr.as_ptr(); |
| let len = self.repr.as_ref().len(); |
| slice::from_raw_parts_mut(ptr.cast(), len) |
| } |
| } |
| |
| const_assert_eq!( |
| mem::size_of::<Option<RustSlice>>(), |
| mem::size_of::<RustSlice>(), |
| ); |