Messages in this thread | | | From | Andreas Hindborg <> | Subject | Re: [PATCH v2 4/5] rust: types: implement `ForeignOwnable` for the unit type | Date | Wed, 01 Feb 2023 10:58:27 +0100 |
| |
Wedson Almeida Filho <wedsonaf@gmail.com> writes:
> This allows us to use the unit type `()` when we have no object whose > ownership must be managed but one implementing the `ForeignOwnable` > trait is needed. > > Signed-off-by: Wedson Almeida Filho <wedsonaf@gmail.com> > Reviewed-by: Vincenzo Palazzo <vincenzopalazzodev@gmail.com> > ---
Reviewed-by: Andreas Hindborg <a.hindborg@samsung.com>
> v1 -> v2: use `NonNull::dangling` to generate pointer > > rust/kernel/types.rs | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/rust/kernel/types.rs b/rust/kernel/types.rs > index 411655eca3e9..9d0fdbc55843 100644 > --- a/rust/kernel/types.rs > +++ b/rust/kernel/types.rs > @@ -85,6 +85,18 @@ impl<T: 'static> ForeignOwnable for Box<T> { > } > } > > +impl ForeignOwnable for () { > + type Borrowed<'a> = (); > + > + fn into_foreign(self) -> *const core::ffi::c_void { > + core::ptr::NonNull::dangling().as_ptr() > + } > + > + unsafe fn borrow<'a>(_: *const core::ffi::c_void) -> Self::Borrowed<'a> {} > + > + unsafe fn from_foreign(_: *const core::ffi::c_void) -> Self {} > +} > + > /// Runs a cleanup function/closure when dropped. > /// > /// The [`ScopeGuard::dismiss`] function prevents the cleanup function from running.
| |